Remove all teams, users, and auth endpoints from the FastAPI backend

[CheesyLaZanya]

Teams, users, and authentication endpoints will all be handled on the Svelte backend now, keeping app endpoints separate from content/python endpoints.

As such we'll need to clean up all the FastAPI endpoints we had made around users, teams, and authentication in general.

[fearnworks]

We also need to make sure the server is not exposed outside of the docker network if we are removing auth.

Are we confident this is not opening up a security vulnerability?

[Tomislaw]

Fastapi will be available on different port than svelte app. We just need to make sure that on the nginx side we won't be exposing ports other than the one svelte app is running.