✨ 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.

检查现有的 LSP client 实现以及与所列通知和事件 capabilities 相关的 Language Server Protocol 规范。确定当前尚未处理的 server 消息，然后为每项 capability 定义支持的 handler 范围和验证方法。

由索引模型根据 Issue 内容生成。