Implement semantic tokens (for highlighting)

[FelipeLema]

Fixes #847
pick up from #961

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[FelipeLema]

that's weird... I thought I added the last missing for TextDocumentClientCapabilities for semanticTokens::Union{SemanticTokensClientCapabilities,Missing}

can we trigger CI for this again?

[PhilippPolterauer]

I would love to use this feature. Is there anyway to assist in the development?
Or maybe test it for functionality?

[FelipeLema]

the skeleton is there and it works, although it needs to be polished. Namely, the column-row indices seem to be off, but I haven't had time to pin the bug: I can see some coloring that has the row-col off, but I'm having trouble reproducing them as a minimum working example for unit tests. The bugfix should be easy, probably just a +1 or -1 missing somewhere... the trouble is reproducing the error.

If you've setup your IDE manually (neovim, emacs... anything but VSCode), then it should be fairly easy to point to this code and try it out:
1- clone my repo locally
2- checkout the semantic-tokens-847
3- point the setup code / script to the repo you cloned

one thing that can also be worked on is adding matching cases to semantic_token_kind(), specially leveraging external_env::StaticLint.ExternalEnv for semantic context. For example, you can add the case and return an "Argument" token by copying the code for the static lint rule for "unused argument".

I'd recommend using tests for working on semantic_token_kind()

[caleb-allen]

@FelipeLema was this functionality completed elsewhere?

[FelipeLema]

@caleb-allen "semantic tokens for julia language server"? not that I know of
"semantic tokens for any language"? clangd & sumneko lua

[caleb-allen]

@FelipeLema what was the reason for closing this PR?

[FelipeLema]

@caleb-allen I don't see myself finishing it in the near future. I tried squeezing some time the last few weeks, but no dice.

[caleb-allen]

@FelipeLema I'm interested in picking up where you left off, however I hit a 404 when I try to access the repo you linked above https://github.com/FelipeLema/LanguageServer.jl

Are you willing to share your latest work so that I could potentially pick it up?

[FelipeLema]

oh, I deleted that repo recently (that probably auto-closed this PR)

I've re-uploaded the semantic-tokens-847 branch to https://codeberg.org/FelipeLema/LanguageServer.jl

[caleb-allen]

@FelipeLema I see. Thanks for re-uploading it!