Adds static modifier to semantic tokens where appropriate.

[LucasSantos91]

This enables coloring local and static variables differently:

It does not affect VS Code's default themes:

[Techatrix]

The test coverage for semantic tokens should be updated. You can use zig build test -Dtest-filter="lsp_features.semantic_tokens" to run them.

I pushed a commit to your PR that should improve the error message from the tests when it reports incorrect token modifiers. Hope that helps.

Also be aware that this PR will need to be rebased if #2244 is merged.

[LucasSantos91]

I've implemented all the tests.
I refactored my code and some of the code that was already present to decrease nesting.
I think I've got the logic to a good spot.
If we can determine that a token is either a type or a function, we don't add the static modifier, as it doesn't really make sense for them.
If the type cannot be determined, we decide whether to add the static modifier based solely on the scope of its declaration.
The only desirable thing that has not been added is that tokens of type .property don't inherit the static modifier from their parents. I could not find a way to do that without iterating up the chain of field accesses, like I had done previously.

[Techatrix]

Looks good! Thanks for your work.