perf: common utils. 包括Md5, PK, PK2, UUID, SortedTags, DictedTagstring等函数

[n4mine]

优化效果见如下benchmark结果

goos: darwin
goarch: amd64
pkg: github.com/n4mine/falcon-plus/common/utils
Benchmark_PK-4                            	 2000000	       632 ns/op	     112 B/op	       4 allocs/op
Benchmark_PK_orig-4                       	 2000000	       702 ns/op	     160 B/op	       7 allocs/op
Benchmark_PK2-4                           	10000000	       126 ns/op	      32 B/op	       1 allocs/op
Benchmark_PK2_orig-4                      	10000000	       204 ns/op	      64 B/op	       3 allocs/op
Benchmark_UUID-4                          	 2000000	       826 ns/op	     128 B/op	       4 allocs/op
Benchmark_UUID_orig-4                     	 2000000	       894 ns/op	     200 B/op	       9 allocs/op
Benchmark_Md5-4                           	 5000000	       294 ns/op	      64 B/op	       2 allocs/op
Benchmark_Md5_orig-4                      	 3000000	       582 ns/op	     192 B/op	       5 allocs/op
Benchmark_SortedTags_1pair-4              	10000000	       228 ns/op	       3 B/op	       1 allocs/op
Benchmark_SortedTags_1pair_orig-4         	 5000000	       309 ns/op	      35 B/op	       3 allocs/op
Benchmark_SortedTags_2pairs-4             	 3000000	       484 ns/op	      72 B/op	       3 allocs/op
Benchmark_SortedTags_2pairs_orig-4        	 2000000	       878 ns/op	     176 B/op	      10 allocs/op
Benchmark_SortedTags_3pairs-4             	 2000000	       618 ns/op	      96 B/op	       3 allocs/op
Benchmark_SortedTags_3pairs_orig-4        	 1000000	      1236 ns/op	     248 B/op	      13 allocs/op
Benchmark_SortedTags_4pairs-4             	 2000000	       770 ns/op	     112 B/op	       3 allocs/op
Benchmark_SortedTags_4pairs_orig-4        	 1000000	      1607 ns/op	     332 B/op	      17 allocs/op
Benchmark_SortedTags_5pairs-4             	 2000000	       924 ns/op	     144 B/op	       3 allocs/op
Benchmark_SortedTags_5pairs_orig-4        	 1000000	      1878 ns/op	     432 B/op	      20 allocs/op
Benchmark_SortedTags_6pairs-4             	 1000000	      1086 ns/op	     160 B/op	       3 allocs/op
Benchmark_SortedTags_6pairs_orig-4        	 1000000	      2319 ns/op	     499 B/op	      23 allocs/op
Benchmark_DictedTagstring_1pair-4         	 5000000	       259 ns/op	     352 B/op	       3 allocs/op
Benchmark_DictedTagstring_1pair_orig-4    	 5000000	       339 ns/op	     384 B/op	       4 allocs/op
Benchmark_DictedTagstring_2pairs-4        	 5000000	       450 ns/op	     368 B/op	       3 allocs/op
Benchmark_DictedTagstring_2pairs_orig-4   	 3000000	       561 ns/op	     432 B/op	       5 allocs/op
Benchmark_DictedTagstring_3pairs-4        	 3000000	       399 ns/op	     384 B/op	       3 allocs/op
Benchmark_DictedTagstring_3pairs_orig-4   	 2000000	       637 ns/op	     480 B/op	       6 allocs/op
Benchmark_DictedTagstring_4pairs-4        	 3000000	       485 ns/op	     400 B/op	       3 allocs/op
Benchmark_DictedTagstring_4pairs_orig-4   	 2000000	       813 ns/op	     528 B/op	       7 allocs/op
Benchmark_DictedTagstring_5pairs-4        	 3000000	       579 ns/op	     416 B/op	       3 allocs/op
Benchmark_DictedTagstring_5pairs_orig-4   	 1000000	      1026 ns/op	     576 B/op	       8 allocs/op
Benchmark_DictedTagstring_6pairs-4        	 2000000	       664 ns/op	     432 B/op	       3 allocs/op
Benchmark_DictedTagstring_6pairs_orig-4   	 1000000	      1151 ns/op	     624 B/op	       9 allocs/op
PASS
ok  	github.com/n4mine/falcon-plus/common/utils	64.320s