[clangd] Implement configs to stop clangd produce a certain semantic tokens

This patch introduces the following configurations to .clangd:

```
SemanticTokens:
    DisabledKinds: [ ... ]
    DisabledModifiers: [ ... ]
```

Based on the config, clangd would stop producing a certain type of semantic tokens from the source file.

Fixes https://github.com/clangd/clangd/discussions/1598

Reviewed By: nridge

Differential Revision: https://reviews.llvm.org/D148489