Feature Request: Support for Semantic Tokens / Semantic Highlighting

[AgustinOrdonez]

Hello,

First of all, thank you for maintaining asm-lsp.

I noticed that asm-lsp currently does not advertise the semanticTokensProvider capability during LSP initialization, which means editors cannot take advantage of semantic highlighting.

For example, in Neovim, the server capabilities currently look roughly like:

{
  completionProvider = ...,
  definitionProvider = true,
  diagnosticProvider = ...,
  documentSymbolProvider = true,
  hoverProvider = true,
  referencesProvider = true,
  signatureHelpProvider = ...,
  textDocumentSync = ...
}

but there is no:

semanticTokensProvider = {
  ...
}

Is support for the LSP Semantic Tokens protocol planned? If not, would you consider adding it?

I think this would significantly improve the editing experience.
Thank you.