[ty] Improve disambiguation of types via fully qualified names

[AlexWaygood]

Summary

Some small followups to #19850:

• Disambiguate classes (where appropriate) in invalid-return-type as well as invalid-assignment
• Extend the disambiguation to work with the Display of generic aliases

Test Plan

Snapshot added

[github-actions]

Diagnostic diff on typing conformance tests

No changes detected when running ty on typing conformance tests ✅

[github-actions]

mypy_primer results

Changes were detected when running on open source projects

prefect (https://github.com/PrefectHQ/prefect)
- src/prefect/server/api/artifacts.py:46:12: error[invalid-return-type] Return type does not match returned value: expected `Artifact`, found `Artifact`
+ src/prefect/server/api/artifacts.py:46:12: error[invalid-return-type] Return type does not match returned value: expected `src.prefect.server.schemas.core.Artifact`, found `src.prefect.server.database.orm_models.Artifact`

No memory usage changes detected ✅

[carljm]

Thank you!