Investigate adding syntax highlighting

[gnikit]

The language server can provide syntax highlighting. It would be interesting to explore potential improvements using this feature.

I would not consider adding full-blown support like in VSCode but if the server would serve additional scopes on an existing syntax that would be extremely beneficial since functions are not currently highlighted in any TextMate grammar file I have seen.

[gnikit]

I need to implement semantic tokens request fulfillment: https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#textDocument_semanticTokens

[ivan-pi]

Speaking of syntax highlighting, I find it nice to be able to highlight namelists too. I wrote a configuration for Notepad++ in the past: https://gist.github.com/ivan-pi/18babf715c098b3225537cf63a70402e