Like a5f3318f3b, this proves that the new dispatcher conversion works for fire-and-forget style dispatches too. This is another obvious-if-broken and generally safe conversion to make.
Other actions which can be dispatched this way have been excluded for reasons mentioned in the Action enum's comments.
The "New Recovery Method" dialog would show if either the recovery method had
been changed or removed, but the dialog text didn't make much sense for the
removed case.
This adds a separate dialog customized for the removed case.
Fixes https://github.com/vector-im/riot-web/issues/8046.
