Migrate from argparse to craft_cli

[freyes]

Python's argparse does its job, although it's a bit strict, for example global arguments must be passed before the subcommand keyword, this makes the cli look not great, this is solved out of the box by craft_cli and it would be give this tool a more consistent UI when contrasted with the other tools of charming ecosystem (e.g. charmcraft).

https://github.com/canonical/craft-cli