Clean up the repo a bit, and add some unit tests

• Add a bunch of unit tests for different workflows
• Rework the different util modules and merge them where relevant
• Resolve some TODO items in config.py (netmasks are now validated)
• Add some :term: directives to docstrings
• Resolve a pytest warning about an unregistered mark @pytest.mask.workflow

docs/source/module/products/index.rst

 ``gso.products``
 ================
 
+.. automodule:: gso.products
+   :members:
+   :show-inheritance:
+
 Subpackages
 -----------