Include diagnostic error codes in tooltips

[daizutabi]

Description

Currently, diagnostic message and source are displayed in tooltips. However, the diagnostic code (e.g., reportUnusedImport) is missing.

Proposed Change

It would be helpful if the diagnostic rendering included the error code alongside the source.

Justification

1. Searchability: Users can easily copy the specific error code (like reportUnusedImport) to search for detailed documentation or solutions.
2. Configuration: Users need these codes to configure lint rules (e.g., adding them to the ignore list in pyproject.toml).
3. IDE Standard: IDEs like VS Code follow this pattern by displaying both the source and the error code.

Desired format

message
source(code)

Example:

Import "os" is not accessed
basedpyright(reportUnusedImport)

[mscolnick]

Hey @daizutabi, I agree the code would be better. Is that something you'd want to take on? If not, no worries, I can get to it this week.

[daizutabi]

I'm happy to hear that. I'd be grateful if you could take care of it. Looking forward to the update!