Adds code quality

[edbeeching]

It is about time we have some code quality standards on the project. At least for the python part. This PR adds a github action to test for quality and also formats all files to meet this standard.

The only downside is that it makes blaming harder as it touches almost all files.

[Ivan-267]

This is a good idea. Just as a note, make doesn't work directly on Windows, but running the commands manually did work.

Either a script can be written for those commands on Windows, and/or some compatibility tool can be installed to allow using Make (e.g. I just locally added the style/quality lines to a .bat file I called StyleQuality.bat):

black --line-length 120 --target-version py310 tests godot_rl examples
isort -w 120 tests godot_rl examples
black --check --line-length 120 --target-version py310 tests godot_rl examples
isort -w 120 --check-only tests godot_rl examples
flake8 --max-line-length 120 tests godot_rl examples

Running that file from powershell within a conda env works.