🐞 Language Server Requests Should Timeout

### Description

There is a chance that language servers (maliciously or due to a bug) may not respond to requests made by the client (CodeEdit). This can cause problems, for example:

- Memory build up as syntax token requests pile up with no responses.
- App refusing to quit before the language server exits, but the language server does not respond to the `exit` message.
- UI hanging forever after a request (eg for a definition search).

In each of these cases one solution would be to time out the request. I think our LSP requests should have a default timeout length.

This has the caveat for requests that may take a long time. Those requests will need to be overridable so they can take longer. The same goes for requests that need immediate response (like the `exit` message), which will need to be shorter.

### To Reproduce

The sourcekit-lsp binary that ships with Xcode 16 is bugged, and will not respond to the exit message. This leaves CodeEdit hanging when quitting the app and requires a force quit.

The same LSP does not respond to semantic token requests (despite declaring the capability, this is a bug with sourcekit-lsp). This may cause cached request handlers to build up over time.

### Expected Behavior

Each language server request should have a timeout parameter. This likely means creating a new LanguageServer connection type that passes messages through to another type, but provides a timeout handler for requests. This may be something we can contribute back to the LanguageServer package.

### Version Information

CodeEdit: 0.3.3

### Additional Context

_No response_

### Screenshots

_No response_

Beginne damit, die Behandlung von Language-Server-Anfragen und das Herunterfahren in CodeEdit zu lokalisieren, und reproduziere dann das Problem mit der in Xcode 16 enthaltenen sourcekit-lsp-Binärdatei. Definiere das Timeout-Verhalten für gewöhnliche, lang laufende und sofortige Anfragen; fertig bedeutet, dass Anfragen nicht mehr unbestimmt lange warten und der Exit-Fall das Beenden ermöglicht.

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