Improve error messages for `uv pip install` with `--extra` or `--all-extras` and invalid sources (#11193)
Closes https://github.com/astral-sh/uv/issues/11190
Closes https://github.com/astral-sh/uv/issues/7845
This error message was copied over from `uv pip compile` (presumably)
but makes way more sense there than here.