[red-knot] Add more tests for `*` imports (#16955)
## Summary
This PR separates out the entirely new tests from
https://github.com/astral-sh/ruff/pull/16923 into a standalone PR. I'll
rebase https://github.com/astral-sh/ruff/pull/16923 on top of this
branch.
The reasons for separating it out are:
- It should make it clearer to see in
<https://github.com/astral-sh/ruff/pull/16923> exactly how the
functionality is changing (we can see the assertions in the tests
_change_, which isn't so obvious if the tests are entirely new)
- The diff on <https://github.com/astral-sh/ruff/pull/16923> is getting
pretty big; this should reduce the diff on that PR somewhat
- These tests seem useful in and of themselves, so even if we need to do
a wholesale revert of <https://github.com/astral-sh/ruff/pull/16923> for
whatever reason, it'll be nice to keep the tests
## Test Plan
`cargo test -p red_knot_python_semantic`
