fix(biome_js_parser): report error when using u and v flag at the same time

[nissy-dev]

Summary

This is a follow up PR of #619

Based on #619 (comment), I modified the parser to report an error when the u and v flags are used at the same time.
This PR is a follow up PR, so I don't update changelog.

Test Plan

I added some parser tests.

[github-actions]

Parser conformance results on

js/262

Test result	main count	This PR count	Difference
Total	49701	49701	0
Passed	48720	48721	✅ ⏫ +1
Failed	981	980	✅ ⏬ -1
Panics	0	0	0
Coverage	98.03%	98.03%	+0.00%

🎉 Fixed (1):

built-ins/RegExp/prototype/unicodeSets/uv-flags.js

jsx/babel

Test result	main count	This PR count	Difference
Total	40	40	0
Passed	37	37	0
Failed	3	3	0
Panics	0	0	0
Coverage	92.50%	92.50%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	6322	6322	0
Passed	2036	2036	0
Failed	4286	4286	0
Panics	0	0	0
Coverage	32.20%	32.20%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	662	662	0
Passed	592	592	0
Failed	70	70	0
Panics	0	0	0
Coverage	89.43%	89.43%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	17646	17646	0
Passed	13454	13454	0
Failed	4190	4190	0
Panics	2	2	0
Coverage	76.24%	76.24%	0.00%

[ematipico]

"Invalid", capital letter. "flag.", with dot at the end