Special handling of comment delimiters in StreamScanner

[angelamayxie]

fixes #10694

[coffeegoddd]

@angelamayxie DOLT

read_tests	from_latency	to_latency	percent_change
covering_index_scan	0.57	0.55	-3.51
groupby_scan	10.09	9.91	-1.78
index_join	1.86	1.82	-2.15
index_join_scan	1.39	1.39	0.0
index_scan	21.89	21.89	0.0
oltp_point_select	0.27	0.27	0.0
oltp_read_only	5.28	5.28	0.0
select_random_points	0.53	0.53	0.0
select_random_ranges	0.56	0.56	0.0
table_scan	21.89	21.89	0.0
types_table_scan	65.65	66.84	1.81

write_tests	from_latency	to_latency	percent_change
oltp_delete_insert	6.32	6.32	0.0
oltp_insert	3.13	3.13	0.0
oltp_read_write	11.24	11.45	1.87
oltp_update_index	3.19	3.19	0.0
oltp_update_non_index	3.13	3.13	0.0
oltp_write_only	5.99	5.99	0.0
types_delete_insert	6.79	6.79	0.0

[coffeegoddd]

@angelamayxie DOLT

comparing_percentages
100.000000 to 100.000000

version	result	total
94230ee	ok	5937471

version	total_tests
94230ee	5937471

correctness_percentage
100.0

[coffeegoddd]

@angelamayxie DOLT

test_name	from_latency_p95	to_latency_p95	percent_change
tpcc-scale-factor-1	61.08	61.08	0.0

test_name	from_server_name	from_server_version	from_tps	to_server_name	to_server_version	to_tps	percent_change
tpcc-scale-factor-1	dolt	0294acf	37.81	dolt	94230ee	38.04	0.61

[fulghum]

Very nice!