Setup unit tests

[semagnum]

Needed unit tests:

• Unit tests for validating each light tool can run:
  • [X] light paint
  • [X] mesh light paint
  • [X] tube light paint
  • [X] sky paint
  • [X] shadow paint
• Unit test to validate each axis:
  • [X] X, Y, Z
  • [X] normal
  • [X] rim lighting
  • [X] rim lighting without camera (should error)
• Unit tests to validate ray visibility
  • [X] light paint
  • [X] mesh/tube light/shadow paint
  • [X] sky paint
• [X] unit test to validate relative power
• [X] unit test to validate area lamp orientation
• [ ] unit tests to validate sky texture and sun direction

[semagnum]

Windows access errors on Blender 3.4 makes pytest at best unwieldy. Strangely nView's local testing still works fine. Probably an environment issue, but not entirely sure. Will look into later after release.

[semagnum]

Trying to run tests without Blender running in the background isn't really feasible, as bpy is being used directly in most modules. I think I'll just mark this as a won't fix for now. Hopefully look into it later.

[semagnum]

Found and tested a new way of doing unit tests that's cleaner without blender-addon-tester. Will figure out some deterministic unit tests for the tools.

[semagnum]

Sky texture and sun orientation deemed a little complicated for unit tests, will add it at a future time. These starting tests will be sufficient.

Closing. No release made since this is mainly for devs.