feat(#29): add basic LSP with support for Nuxt

[phoenix-ru]

Contributes to #29

This adds a super basic LSP server tailored for use with Nuxt projects. The server was born out of frustration of multiple different tools not working with medium-to-large (50K+ LOC) Nuxt codebases.

Currently only implements the very simple functionality:

• Autocompletion of Nuxt auto-importable component and symbol names (see https://nuxt.com/docs/4.x/examples/features/auto-imports) - with limitation to only prefix-matching and no context awareness yet;
• Click-through on known components and symbol names (same set as for autocompletion);
• Displaying parsing errors as diagnostics;

Try it

For a (very concise) guide on how to use it, refer to crates/fervid_lsp/README.md