[red-knot] Goto type definition

[MichaReiser]

Summary

Implement Goto type definition support for Red Knot's LSP.

TODOs:

• Add some tests
• Putting the cursor right between a call's object and the opening ( returns no results because it then finds the Arguments node instead of the object identifier. We likely need a tie-breaker function. r-a uses a TokenAtOffset enum that returns None, Single or Between and then prioritizes Between. https://github.com/rust-analyzer/rowan/blob/e73210820dcd990b1b028d524efacbd619144fc3/src/api.rs#L213-L216

Known limitations

• Types defined in the vendored typeshed aren't supported because the client can't open those files (we can either implement our own file protocol and handler OR extract the typeshed files and point there)
• Some nodes and types aren't supported yet. I added inline TODOs explaining what's missing
• We may want to have a higher level API for the LSP that doesn't call semantic queries directly. I intentionally decided not to design that API just yet.

[MichaReiser]

This is a bugfix that I copied over from ruff-server

[github-actions]

mypy_primer results

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[github-actions]

ruff-ecosystem results

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Formatter (preview)

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