[Python APIView] make sure we support best practices for accessing annotations

[kristapratico]

See here: https://docs.python.org/3.10/howto/annotations.html

There is still a debate whether https://peps.python.org/pep-0563/ will become the default behavior in Python or if https://peps.python.org/pep-0649/ will supersede it. If we follow the best practices to access annotations, I believe we should be okay in either case.