Implement syntactic fold for comments for JS, TS, and TSX

[Daquisu]

This PR implements the first five steps of #31395:

1. Create folds.scm for JavaScript, TypeScript, TSX for comments only (for now) Although the comments are already queried by highlights.scm and text_objects.scm, they are semantically different from querying comments to make them foldable. In the future, we can easily add folds to other syntax structures with this new file. Related: nvim-treesitter uses a folds.scm for each language. TypeScript example.

2. Modify language.rs to add new fields related to folds_query (e.g. add folds_query to the Grammar struct).

3. Create function in multi_buffer.rs to query fold information according to folds.scm on demand.

4. Optimize fold actions to minimize number of folds queries done (e.g. when calling fold_all).

5. Also optimize the fold indicators in the UI.

The optimizations done were done by either:

i. Precomputing a map of fold starting row to fold range (done in fold actions in general).

ii. Minimizing the bytes parsed by the query (done in the UI).

Manual test:

https://github.com/user-attachments/assets/f744bcfd-2499-456c-ab24-d8a139d2a10f

Release Notes:

• Implemented syntactic fold for comments for JavaScript, TypeScript, and TSX.

[maxdeviant]

Seems like we should add the implementation for how folds.scm will be used first before we go defining the folds queries themselves.

[probably-neb]

Hey, I appreciate that you're taking the time to do this. However, I'd much prefer it if you would implement syntax based folding as a single PR, rather than a bunch of small PR's. This will greatly reduce the review burden on us, and allow easy reverting/changing/reworking. My suggestion is that you mark this PR as a draft, and continue working on adding support for the folds.scm files. Thanks again!

[Daquisu]

Thanks for the quick feedback. I was uncertain about the best PR size in this case, so your comment helps a lot.

I will change the PR to draft while I work on it.

[Daquisu]

The PR is ready for review.

Sorry about closing it earlier, somehow I misclicked and did not notice.

[SomeoneToIgnore]

I will close it as things start to conflict and it's been 3 weeks since the last feedback. Overall, looks like a nice idea though.