[Feature Request] User authorization flow for third party sites

[LostLuma]

There doesn't seem to be a proper authorization method on RA at the moment and third party sites have to resort to using no authorization or workarounds such as editing the users motto.

I'd like to be able to simply send the user through an oauth2/openID/.. flow to authorize them, as it's simpler for both the user and me.

Thanks! 👋