Update to pygls 2

[edvilme]

This pull request updates the LSP server implementation in bundled/tool/lsp_server.py to be compatible with pygls version 2 and refactors diagnostic and messaging APIs to use the new methods and types. The changes modernize the codebase, improve clarity, and ensure compatibility with the latest pygls release.

Migration to pygls v2 and API refactoring:

• Updated requirements.in to require pygls>=2, ensuring compatibility with the latest version.
• Replaced imports and usages of server.LanguageServer, workspace.Document, and associated methods with their pygls v2 equivalents (LanguageServer, TextDocument, etc.).
• Refactored diagnostic publishing methods to use text_document_publish_diagnostics and lsp.PublishDiagnosticsParams instead of the deprecated publish_diagnostics. [1] [2] [3]
• Updated messaging functions to use window_log_message and window_show_message with the new parameter objects, replacing the old show_message_log and show_message methods.

Type and method updates for workspace/document handling:

• Changed function signatures and internal logic to use TextDocument instead of workspace.Document, updating all relevant helper and utility functions. [1] [2] [3] [4] [5]

These updates are essential for maintaining compatibility and leveraging improvements in pygls v2.

[edvilme]

Tests fixed to match changes from python/mypy#19115