- codestyle improvements
- reuse TypeEvalContext and PyResolveContext
- check PyDunderAllReference specifically to avoid unwanted side effects
- skip resolving PyTargetExpression
- replace references with import alias in the refactoring, instead of the utility method
- added single reference search for PyStringLiteralExpressionImpl
- cleanup obsolete tests
GitOrigin-RevId: 3e33c880a8fe116a5b98583059c83b7dd67e34a2
