Unify package and PyInstaller CLI

[bede]

Sadly defopt seems to be incompatible with PyInstaller (anntzer/defopt#117 and https://groups.google.com/g/PyInstaller/c/7hIzNQpM57M)

As such cli-upload is provided as an alternative entry point for PyInstaller only, which only exposes the functionality of gpas upload rather than the full defopt CLI with other subcommands available in the Python package.

Assuming there is not a workaround for this issue, either the CLI will need to be duplicated for PyInstaller's with e.g. argparse, or rewritten in something compatible with PyInstaller and subset of Python it supports.

[bede]

Released in 0.6.0