Add support for debugging and testing python in gitpod

I moved away from running everything in the docker. Currently docker is there only for postgres, redis and nginx. Backend as well as frontend are now being run as standalone gitpod tasks.

I've added python manage.py gitpod command with init and dev subcommands:

• init creates a gitpod user and imports the library from funkwhale/catalog to this user.
• dev starts django app with uvicorn and debugpy for VSCode debugging support