Documenting API errors

[monolithed]

Could you please add detailed information to the API documentation about all possible errors, their meanings, and how to handle them? At the moment, understanding the differences between invalid_jwt, invalid_session_cookie, and no_session_cookie_provided requires digging into the code. Additionally, some errors, like invalid_grant, seem to come from external sources and aren't documented in the codebase.

[kevinmitch14]

It would be nice to know if GenericServerException, OauthException etc. can be 'leaked' to the client

[monolithed]

@kevinmitch14, they can #1202 🙂

[kevinmitch14]

I mean is it safe to expose these on the client!