[FEATURE REQUEST] - Add OAuth2 authentication

[ebkr]

What problem does the feature request solve? Allow users to rate mods.

Additional information (optional) Functionality should include the following:

1. New screen to handle logins
2. Ability to save for later or only for the current session.
3. Networks requests such as rating should be handled through a separate class.

[ebkr]

TS requires a session ID to be used in order to rate packages. It's not yet possible to obtain a session ID externally.