refactor(server): decouple analysis from visit logic and simplify definition provider

[ntoulasm]

Summary

This PR reorganizes the language server logic to improve readability and maintainability. It Decouples the generic AST visitation logic from the symbol extraction and analysis logic. It also breaks down the definition provider to smaller functions.

Key Changes

1. Refactored visitor.ts to a generic callback based structural visitor. It now focuses solely on traversing the AST and providing accurate JSON paths.
2. Introduced analyzer.ts a dedicated module for high level document analysis. It uses the visitor to collect symbols.
3. Extracted the SymbolTable type definition and JRefSymbol interface into symbolTable.ts.
4. Updated existing tests to align with the refactoring
   • Renamed visitor.test.ts to analyzer.test.ts, since it verified that symbols are correctly identified during analysis.
5. Added visitor.test.ts with a unit test for the structural traversal itself.