Support Multiple Jellyfin Servers / Separate Auth Providers

[Dan6erbond]

What needs to be done?

• [ ] Separate the Jellyfin servers from the auth providers.
• [ ] Support multiple Jellyfin configurations in jellyfin.
• [ ] Support an auth provider key in the configuration.
• [ ] Allow user to pick which Jellyfin server to log into.
• [ ] Map media to JellyfinItem and remove JellyfinID and JellyfinServerID attributes from entities.