Rewrite static type analyzer tests using the new PubPackageResolutionTest style.

Using this style makes the tests more robust to refactoring the
analyzer, since the tests exercise the analyzer in end-to-end fashion.

Bug: dart-lang/sdk#44522
Change-Id: Ia036d5d32621019841b5a5cf44f43ab8761f98aa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/224621
Reviewed-by: Konstantin Shcheglov <[email protected]>
Commit-Queue: Paul Berry <[email protected]>

Author: stereotype441