python: Add py.typed marker file

[bkeryan]

What does this Pull Request accomplish?

Add a py.typed marker file so type checkers like Mypy and Pyright know that traceloggingdynamic has type hints.

To enable adding this marker file, convert the top-level traceloggingdynamic module into an import package and update setup.cfg to find packages.

Why should this Pull Request be merged?

Fixes #57

What testing has been done?

Built and ran tests with Python 3.11.9:

python -m build
pip install .\dist\traceloggingdynamic-1.0.0-py3-none-any.whl
python .\tests\traceloggingdynamictest.py -v

Opened the sdist and wheel in 7-Zip to verify that the package's __init__.py and py.typed files are present.

Ran mypy on a project that uses traceloggingdynamic.

[bkeryan]

@microsoft-github-policy-service agree company="Emerson"

[idigdoug]

@microsoft-github-policy-service agree company="Emerson"

Thanks a bunch!

[Robo210]

Pushed to pypi as version 1.0.1