Summary

Implements a rudimentary uv pip wheel command. This is simply a repackaged uv pip install that short-circuits at the actual install step and instead takes the cached wheels and zips them up. Marked as draft because I don't really like my implementation, it's a bit messy and duplicates a lot of uv pip install, and there's questions about the semantics of pip wheel that I don't have enough knowledge to answer.

Resolves #1681

TODO:

1. De-duplicate most of the logic between uv pip wheel and uv pip install
2. Decide whether a notion of resolving dependencies is really how pip wheel is supposed to behave
3. Introduce a separate crate for writing a zipped wheel (I basically just copied from uv-build-backend)
4. Write tests / integration tests.

(On the last point: I can uv pip wheel and install said wheels, and they're identical to uv pip wheel, sans the records being slightly different due to console scripts not being included. I do think this is an actual bug though, which is why I want to use the logic in uv-build-backend which has already solved this, though it will need to be in a new crate).