Global Refactoring: Transition from `sessionId` to `documentUri` and Major Workspace Enhancements

[mkslanc]

This PR introduces substantial refactoring and the addition of critical workspace functionalities. These changes are focused on improving the codebase's consistency, expanding client capabilities, and enhancing user experience.

Summary of Changes:

1. Global Refactoring:

   • Refactored the codebase to replace all instances of sessionId with documentUri. This transition improves the clarity and consistency of references within the application.

2. Workspace and Document Features:

   • workspace/executeCommand: Added support for executing workspace commands, allowing for a broader range of workspace-level operations.
   • workspace/applyEdit: Implemented the ability to apply edits across the workspace dynamically, enhancing flexibility in managing workspace changes.
   • workspace/didChangeWorkspaceFolders: Introduced functionality to handle changes in workspace folders, enabling the client to respond dynamically to such changes.
   • textDocument/codeAction: Expanded support for code actions, allowing users to receive more targeted and useful in-editor suggestions and actions.

3. UI and UX Improvements:

   • Added a new lightbulb component, providing intuitive visual cues for available code actions.
   • Separated styles into distinct files, improving the maintainability and organization of the codebase.

4. Demo Enhancements:

   • Created a demo that showcases the file API alongside the newly integrated workspace capabilities, illustrating the practical application of these features.