mod_http_oauth2: Allow user to decide which requested scopes to grant These should at the very least be shown to the user, so they can decide whether to grant them. Considered whether to filter the requested scopes down to actually understood scopes that would be granted, but decided that this was a bit complex for a first step, since role role selection and other kinds of scopes are mixed into the same field here.

This module discards typing notifications sent to a bare host JID,
preventing error replies to be sent. These errors are harmless but can
be annoying sometimes if your client shows them prominently.