LSP: Implement Phase 2 Endpoints

[0101]

Name	Type	Direction	Category	Priority / Dev phase	Supported by FSAC	Note
completionItem/resolve	Request	↩️	Language features	2	✅
textDocument/completion	Request	↩️	Language features	2	✅
textDocument/declaration	Request	↩️	Language features	2
textDocument/definition	Request	↩️	Language features	2	✅
textDocument/hover	Request	↩️	Language features	2	✅
textDocument/implementation	Request	↩️	Language features	2	✅
textDocument/references	Request	↩️	Language features	2	✅
textDocument/semanticTokens/full/delta	Request	↩️	Language features	2		maybe not needed
textDocument/semanticTokens/range	Request	↩️	Language features	2		maybe not needed
textDocument/typeDefinition	Request	↩️	Language features	2	✅
workspace/semanticTokens/refresh	Request	↩️	Language features	2	✅