[Code Search, II] A tree-sitter parser alternative

[EagleoutIce]

In #1125 we explored the capabilities of tree-sitter for node.js (maybe even the wasm binding 😁) and within this issue we want to try it out as an alternative to the R dependency we currently have (and suffer from :D). For this I have the following wishes:

1. Offer an Alternative R Parser Abstraction, it probably requires a slightly different normalization to take place
2. Allow the configuration and startup flags to select the alternative
3. Evaluate how well the parser performs wrt. the default R parser

Additionally we want the following issues to spawn from this:

• Integration into the extensions
• As an alternative for the benchmarking
• To update the sample and vscode extension regarding the default dependencies