Rewrite build tools

[vkbo]

Summary:

This PR:

• Rewrites the pkgutils.py file to use argprase and pathlib everywhere.
• Splits the GitHub Actions build job into one per platform.
• Adds build job for Windows.
• Drops the intermediate zip file for Windows build and build directly from source.

Related Issue(s):

Reviewer's Checklist:

• The header of all files contain a reference to the repository license
• The overall test coverage is increased or remains the same as before
• All tests are passing
• All flake8 checks are passing and the style guide is followed
• Documentation (as docstrings) is complete and understandable
• Only files that have been actively changed are committed