feat: basic class selector parsing

[ematipico]

Summary

This PR adds basic parsing of CSS class selector.

I removed some nodes from the grammar because they weren't needed.

Test Plan

Added basic tests

[github-actions]

Parser conformance results on

js/262

Test result	main count	This PR count	Difference
Total	48863	48863	0
Passed	47808	47808	0
Failed	1055	1055	0
Panics	0	0	0
Coverage	97.84%	97.84%	0.00%

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	6212	6212	0
Passed	1764	1764	0
Failed	4448	4448	0
Panics	0	0	0
Coverage	28.40%	28.40%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	639	639	0
Passed	573	573	0
Failed	66	66	0
Panics	0	0	0
Coverage	89.67%	89.67%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	17224	17224	0
Passed	13121	13121	0
Failed	4103	4103	0
Panics	0	0	0
Coverage	76.18%	76.18%	0.00%

[denbezrukov]

Could you please share your strategy for situations where we might need to abandon and return as absent, rather than completing and returning bogus kind?

[ematipico]

I don't have a clear strategy in mind yet, but I've had some ideas while starting this work, still it's best if we discuss them.

For rules, I thought we could bogus+recover in the prelude and in the block.

This would allow us to parse cases like:

.foo }
.bar {}

.686 {}
.bar {}

Although, I'm not sure about the prelude of the rule.

Or maybe we should have a big CssBogusRule? What do you think?

[denbezrukov]

I agree with you, let's try to use a recovery strategy.