Rough poc for automated testing

[AdrianDeWinter]

Jut a rough sketch for what this might look like, for details see #181 .

This could run tests in two ways:

• Via console, utilizing blender_addon_tester. Works headless, and across windows and linux (even in containers).
• As python scripts through the VSCode Blender integration. This loses access to pytest, unless one messes with the permissions on the bundled python interpreter to get pip working inside of blender

To quickly run these tests via docker:
docker run --rm -v .:/code -w /code python:3.10 /bin/bash -c ./run_tests.sh
Or, if you want to cache blender versions instead of redownloading them every time:
docker run --rm -v .:/code -v some_dir:/blender_versions -e BLENDER_CACHE=/blender_versions -w /code python:3.10 /bin/bash -c ./run_tests.sh

To run them locally:

• pip install pytest blender_addon_tester-0.10.2-py3-none-any.whl (I had to build the package from source, the version on PyPi... has issues)
• python -m pytest .