✨ LSP Event & Notification Handling

### Description

Language servers can send clients (CodeEdit) notifications and events we should respond to. These include logging ([[1]](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#logTrace), [[2]](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#window_logMessage)), [show messages](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#window_showMessage), showing [progress](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#window_workDoneProgress_create), [opening a file](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#window_showDocument) and a lot more.

Right now our client implementation receives notifications and events but does nothing with them. This issue is a tracking issue for implementing handlers for each capability a server might use.

檢視現有的 LSP client 實作，以及與所列通知和事件 capabilities 相關的 Language Server Protocol 規格。確認目前尚未處理的 server 訊息，接著為每項 capability 定義支援的 handler 範圍與驗證方法。

由索引模型根據 Issue 內容生成。