FR: Add emacs-lsp-booster support

[Dietr1ch]

emacs-lsp-booster claims to improve the performance on both, lsp-mode and eglot, so it'd be nice if rustic checked if it was available and used it to launch the user's LSP server.

I think the change would be just wrapping the LSP command with emacs-lsp-booster %command% if the lsp-server is supported by it¹ and plist deserialisation is enabled.

Footnotes

1. I think it just requires running through stdin/stdout, which I suspect rust-analyzer (and rls) support. ↩