Recognize wildcard-imported Literal annotations

[ShipItAndPray]

Summary

• recognize bare Literal as a typing import when it comes from from typing import * or from typing_extensions import *
• keep the fix narrow to the existing Literal special-case in the transformer
• add focused regression coverage for wildcard-imported Literal annotations

Closes #489

Testing

• uv run pytest tests/test_transformer.py -q -k literal_wildcard_import
• uv run pytest tests/test_transformer.py -q
• baseline repro used a one-off script with from typing import * plus @typechecked and failed before this change with NameError: name 'hi' is not defined

[coveralls]

coverage: 94.92% (+0.009%) from 94.911% — ShipItAndPray:fix-489-wildcard-literal-recognition into agronholm:master

[agronholm]

Why is Literal special-cased here?

[agronholm]

Never mind, I get it now. I had to refresh my memory a bit.

[agronholm]

This still requires a changelog entry.