Remove the CHIPClusters ReadAttribute* APIs.

[bzbarsky-apple]

They were unused except by chip-tool. chip-tool is switched to use
the type-safe read API.

Problem

Command-line chip-tool can't read nullable attributes properly (i.e. if the value is null). And it's using the CHIPClusters APIs that nothing else uses.

Change overview

See above.

Testing

Manually tested a read of a null-valued attribute by hacking chip-tool to write a null value to it (which does not work normally work). Tested some reads of non-null attributes as well.

[github-actions]

PR #12652: Size comparison from 5c70530 to 128fad7

Increases above 0.2%:

platform	target	config	section	5c70530	128fad7	change	% change
linux	chip-tool	debug	(read/write)	200040	201512	1472	0.7
			.data.rel.ro	158600	160072	1472	0.9
			.rodata	313777	334449	20672	6.6

Increases (1 build for linux)

platform	target	config	section	5c70530	128fad7	change	% change
linux	chip-tool	debug	(read only)	6651717	6661157	9440	0.1
			(read/write)	200040	201512	1472	0.7
			.data.rel.ro	158600	160072	1472	0.9
			.rodata	313777	334449	20672	6.6

Decreases (4 builds for esp32, linux)

platform	target	config	section	5c70530	128fad7	change	% change
esp32	all-clusters-app	m5stack	(read only)	956475	955527	-948	-0.1
			(read/write)	439528	439480	-48	-0.0
			.flash.rodata	208132	208084	-48	-0.0
			.flash.text	951091	950143	-948	-0.1
linux	chip-tool	debug	.text	5933045	5918213	-14832	-0.2
	ota-requestor-app	debug	(read only)	1516993	1512449	-4544	-0.3
			(read/write)	78152	78120	-32	-0.0
			.data.rel.ro	29720	29704	-16	-0.1
			.text	1271362	1266866	-4496	-0.4
	tv-app	debug	(read only)	2051945	2047377	-4568	-0.2
			(read/write)	320320	320288	-32	-0.0
			.data.rel.ro	64240	64208	-32	-0.0
			.text	1721602	1717106	-4496	-0.3

Full report (39 builds for efr32, esp32, k32w, linux, mbed, nrfconnect, p6, qpg, telink)

platform	target	config	section	5c70530	128fad7	change	% change
efr32	lighting-app	BRD4161A	(read only)	797468	797468	0	0.0
			(read/write)	120740	120740	0	0.0
			.bss	118912	118912	0	0.0
			.data	1828	1828	0	0.0
			.text	797460	797460	0	0.0
		BRD4161A+rpc	(read only)	825436	825436	0	0.0
			(read/write)	139048	139048	0	0.0
			.bss	137112	137112	0	0.0
			.data	1936	1936	0	0.0
			.text	825428	825428	0	0.0
	lock-app	BRD4161A	(read only)	772152	772152	0	0.0
			(read/write)	118680	118680	0	0.0
			.bss	116888	116888	0	0.0
			.data	1788	1788	0	0.0
			.text	772144	772144	0	0.0
	window-app	BRD4161A	(read only)	774424	774424	0	0.0
			(read/write)	118880	118880	0	0.0
			.bss	117088	117088	0	0.0
			.data	1792	1792	0	0.0
			.text	774416	774416	0	0.0
esp32	all-clusters-app	c3devkit	(read only)	852210	852210	0	0.0
			(read/write)	1295154	1295154	0	0.0
			.dram0.bss	58232	58232	0	0.0
			.dram0.data	14084	14084	0	0.0
			.flash.rodata	169792	169792	0	0.0
			.flash.text	852210	852210	0	0.0
			.iram0.text	62076	62076	0	0.0
		m5stack	(read only)	956475	955527	-948	-0.1
			(read/write)	439528	439480	-48	-0.0
			.dram0.bss	65592	65592	0	0.0
			.dram0.data	34016	34016	0	0.0
			.flash.rodata	208132	208084	-48	-0.0
			.flash.text	951091	950143	-948	-0.1
			.iram0.text	123451	123451	0	0.0
k32w	lighting-app	k32w061+se05x+release	(read/write)	731512	731512	0	0.0
			.bss	79408	79408	0	0.0
			.data	1860	1860	0	0.0
			.text	644444	644444	0	0.0
	lock-app	k32w061+debug	(read/write)	622212	622212	0	0.0
			.bss	70072	70072	0	0.0
			.data	1828	1828	0	0.0
			.text	544512	544512	0	0.0
	shell	k32w061+debug	(read/write)	688120	688120	0	0.0
			.bss	81720	81720	0	0.0
			.data	1800	1800	0	0.0
			.text	598800	598800	0	0.0
linux	all-clusters-app	debug	(read only)	1871081	1871081	0	0.0
			(read/write)	124592	124592	0	0.0
			.bss	50832	50832	0	0.0
			.data	1120	1120	0	0.0
			.data.rel.ro	67216	67216	0	0.0
			.dynamic	592	592	0	0.0
			.got	4120	4120	0	0.0
			.init	27	27	0	0.0
			.init_array	696	696	0	0.0
			.rodata	153717	153717	0	0.0
			.text	1574066	1574066	0	0.0
	bridge-app	debug+rpc	(read only)	1450101	1450101	0	0.0
			(read/write)	74904	74904	0	0.0
			.bss	36464	36464	0	0.0
			.data	1728	1728	0	0.0
			.data.rel.ro	31632	31632	0	0.0
			.dynamic	592	592	0	0.0
			.got	3992	3992	0	0.0
			.init	27	27	0	0.0
			.init_array	480	480	0	0.0
			.rodata	122692	122692	0	0.0
			.text	1222341	1222341	0	0.0
	chip-tool	debug	(read only)	6651717	6661157	9440	0.1
			(read/write)	200040	201512	1472	0.7
			.bss	34728	34728	0	0.0
			.data	1024	1024	0	0.0
			.data.rel.ro	158600	160072	1472	0.9
			.dynamic	592	592	0	0.0
			.got	4496	4496	0	0.0
			.init	27	27	0	0.0
			.init_array	568	568	0	0.0
			.rodata	313777	334449	20672	6.6
			.text	5933045	5918213	-14832	-0.2
	lighting-app	debug+rpc	(read only)	1735881	1735881	0	0.0
			(read/write)	107968	107968	0	0.0
			.bss	42160	42160	0	0.0
			.data	1280	1280	0	0.0
			.data.rel.ro	59136	59136	0	0.0
			.dynamic	608	608	0	0.0
			.got	4144	4144	0	0.0
			.init	27	27	0	0.0
			.init_array	616	616	0	0.0
			.rodata	143281	143281	0	0.0
			.text	1449762	1449762	0	0.0
	ota-provider-app	debug	(read only)	1407641	1407641	0	0.0
			(read/write)	73104	73104	0	0.0
			.bss	39040	39040	0	0.0
			.data	928	928	0	0.0
			.data.rel.ro	27944	27944	0	0.0
			.dynamic	592	592	0	0.0
			.got	4056	4056	0	0.0
			.init	27	27	0	0.0
			.init_array	520	520	0	0.0
			.rodata	124078	124078	0	0.0
			.text	1178706	1178706	0	0.0
	ota-requestor-app	debug	(read only)	1516993	1512449	-4544	-0.3
			(read/write)	78152	78120	-32	-0.0
			.bss	42208	42208	0	0.0
			.data	992	992	0	0.0
			.data.rel.ro	29720	29704	-16	-0.1
			.dynamic	592	592	0	0.0
			.got	4064	4064	0	0.0
			.init	27	27	0	0.0
			.init_array	544	544	0	0.0
			.rodata	136823	136823	0	0.0
			.text	1271362	1266866	-4496	-0.4
	shell	debug	(read only)	823577	823577	0	0.0
			(read/write)	60616	60616	0	0.0
			.bss	16936	16936	0	0.0
			.data	256	256	0	0.0
			.data.rel.ro	38936	38936	0	0.0
			.dynamic	592	592	0	0.0
			.got	3520	3520	0	0.0
			.init	27	27	0	0.0
			.init_array	344	344	0	0.0
			.rodata	84754	84754	0	0.0
			.text	631986	631986	0	0.0
	tv-app	debug	(read only)	2051945	2047377	-4568	-0.2
			(read/write)	320320	320288	-32	-0.0
			.bss	247480	247480	0	0.0
			.data	2768	2768	0	0.0
			.data.rel.ro	64240	64208	-32	-0.0
			.dynamic	592	592	0	0.0
			.got	4456	4456	0	0.0
			.init	27	27	0	0.0
			.init_array	736	736	0	0.0
			.rodata	175436	175436	0	0.0
			.text	1721602	1717106	-4496	-0.3
mbed	all-clusters-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2312128	2312128	0	0.0
			.bss	181412	181412	0	0.0
			.data	5192	5192	0	0.0
			.heap	849840	849840	0	0.0
			.text	1274704	1274704	0	0.0
	lighting-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2300032	2300032	0	0.0
			.bss	173400	173400	0	0.0
			.data	5496	5496	0	0.0
			.heap	857552	857552	0	0.0
			.text	1262632	1262632	0	0.0
	lock-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2273072	2273072	0	0.0
			.bss	172440	172440	0	0.0
			.data	5496	5496	0	0.0
			.heap	858512	858512	0	0.0
			.text	1235672	1235672	0	0.0
	pigweed-app	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	1140008	1140008	0	0.0
			.bss	11756	11756	0	0.0
			.data	4376	4376	0	0.0
			.heap	1020312	1020312	0	0.0
			.text	103392	103392	0	0.0
	shell	CY8CPROTO_062_4343W+release	(read only)	6224	6224	0	0.0
			(read/write)	2047472	2047472	0	0.0
			.bss	156732	156732	0	0.0
			.data	4872	4872	0	0.0
			.heap	874840	874840	0	0.0
			.text	1010072	1010072	0	0.0
nrfconnect	lighting-app	nrf52840dk_nrf52840	(read/write)	894539	894539	0	0.0
			bss	113852	113852	0	0.0
			rodata	99676	99676	0	0.0
			text	605460	605460	0	0.0
		nrf52840dk_nrf52840+rpc	(read/write)	857915	857915	0	0.0
			bss	110200	110200	0	0.0
			rodata	91036	91036	0	0.0
			text	580456	580456	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	820438	820438	0	0.0
			bss	115224	115224	0	0.0
			rodata	94936	94936	0	0.0
			text	535784	535784	0	0.0
	lock-app	nrf52840dk_nrf52840	(read/write)	867123	867123	0	0.0
			bss	111112	111112	0	0.0
			rodata	95796	95796	0	0.0
			text	584832	584832	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	793258	793258	0	0.0
			bss	112524	112524	0	0.0
			rodata	91084	91084	0	0.0
			text	515252	515252	0	0.0
	pigweed-app	nrf52840dk_nrf52840	(read/write)	497463	497463	0	0.0
			bss	51820	51820	0	0.0
			rodata	45852	45852	0	0.0
			text	339492	339492	0	0.0
	pump-app	nrf52840dk_nrf52840	(read/write)	871859	871859	0	0.0
			bss	111024	111024	0	0.0
			rodata	97148	97148	0	0.0
			text	588232	588232	0	0.0
	pump-controller-app	nrf52840dk_nrf52840	(read/write)	865083	865083	0	0.0
			bss	110904	110904	0	0.0
			rodata	95284	95284	0	0.0
			text	583440	583440	0	0.0
	shell	nrf52840dk_nrf52840	(read/write)	779939	779939	0	0.0
			bss	109696	109696	0	0.0
			rodata	73792	73792	0	0.0
			text	521948	521948	0	0.0
		nrf5340dk_nrf5340_cpuapp	(read/write)	694966	694966	0	0.0
			bss	110680	110680	0	0.0
			rodata	68432	68432	0	0.0
			text	442548	442548	0	0.0
p6	all-clusters-app	default	(read/write)	2346536	2346536	0	0.0
			.bss	107692	107692	0	0.0
			.data	2464	2464	0	0.0
			.heap	923184	923184	0	0.0
			.text	1304800	1304800	0	0.0
	light-app	default	(read/write)	2283768	2283768	0	0.0
			.bss	98632	98632	0	0.0
			.data	2336	2336	0	0.0
			.heap	932376	932376	0	0.0
			.text	1242032	1242032	0	0.0
	lock-app	default	(read/write)	2259920	2259920	0	0.0
			.bss	97512	97512	0	0.0
			.data	2296	2296	0	0.0
			.heap	933536	933536	0	0.0
			.text	1218184	1218184	0	0.0
qpg	lighting-app	qpg6100+debug	(read only)	513204	513204	0	0.0
			(read/write)	122332	122332	0	0.0
			.bss	80360	80360	0	0.0
			.data	964	964	0	0.0
			.text	507884	507884	0	0.0
	lock-app	qpg6100+debug	(read only)	487508	487508	0	0.0
			(read/write)	122336	122336	0	0.0
			.bss	79496	79496	0	0.0
			.data	920	920	0	0.0
			.text	482188	482188	0	0.0
	persistent-storage-app	qpg6100+debug	(read only)	108224	108224	0	0.0
			(read/write)	122332	122332	0	0.0
			.bss	36696	36696	0	0.0
			.data	292	292	0	0.0
			.text	102904	102904	0	0.0
telink	lighting-app	tlsr9518adk80d	(read/write)	798310	798310	0	0.0
			bss	80428	80428	0	0.0
			noinit	37160	37160	0	0.0
			text	557916	557916	0	0.0

[woody-apple]

Fast tracking, given this is updating a test tool