Updates, fixes, parametrize versions

[lkubb]

Please excuse me packing all of this into a single PR:

• Makes pre-commit less unhappy with the generated files
• Syntax cleanup/fixes execution module docstring
• Adds the requirements files from the latest release to the repo (Is there a reason they are missing here?), corrects the entries in requirements-files and declares the rest of the extra requirements in setup.cfg since they are not needed for pip-compile
• Ensures pytest-salt-factories is at least 1.0.0rc19, below that will not work anyways
• Allows Python/Salt versions to be parametrized + adds 2 new options for this feature
• Ensures Pylint knows about the minimum supported version
• Removes the hint about <3003 + loaders.py since these versions are long EOL
• Makes the tool default to the most recent oldest currently supported version (3005)
• Python 3.5/3.6 have not been supported for the pre-commit hooks for a while. Make this explicit (drops 3.5/3.6 support for generated projects)
• Syncs/updates pre-commit hooks to the versions used by saltstack/salt@master itself (or the most recent ones supported by Python 3.7, depending on declared version support)
• Bumps the workflow versions
• Doesn't create an apache license if other was specified
• Adds functional tests skeleton
• fixes a race condition in the pylint pre-commit hook
• adds (minion|master)_opts unit test fixtures

Fixes: #34
Fixes: #35
Fixes: #43

The first commit now works without issues again.