Python packaging

[phodina]

Hi, thanks for developing these tools further.

Here's just some glue around the Python code to package it for distros. I'm packaging it for GNU Guix OS.

[phodina]

the whole movement from libexec -> src requires to update SALT first:

https://github.com/steadfasterX/SALT/blob/master/kdzmanager.sh

until this is not done we cannot do that change here. dunno if you wanna take that part as well but this repo does exist only for the reason bc I use it in SALT.. if you can do the changes there as well I would be happy to merge this here though.

Okay, I'll check SALT and make the modifications. The reason why I'm making this PR is that I'd like to have the SALT tool packaged and it depends on the 2 Python subpackages which need some packaging mechanism - pyproject.toml.