Prepare for 1.4

[gijzelaerr]

This:

• removed pytest-asyncio since we don't use it (yet)
• enables python 3.12 build
• restructure getters and setters in utils into sub-modules
• replace pycodestyle with ruff in Make target
• replace pkg_resources with importlib so we don't need setuptools
• replace the ADict with a dict since we didn't use it as a attribute dict anyway
• improve error reporting in case of missing snap7 library

Todo: finish, ruff replaced some of the getter & setter imports, and mypy is not happy with the cdata buffer we use (py 3.12)