Create API for notifications/messages
Use case: App developer wants Orca to present something in speech and/or braille.
Right now, Orca presents anything with a role of notification in response to a state-changed:showing event. Orca also supports ARIA live regions. But for non web apps that don't want to do the notification hackaround, it would be nice to have an easy/straightforward means for an app to pass along a message -- along with various details (e.g. urgency) -- which Orca could then present (based on user settings).
This API would also make it possible to have cleaner live-region implementations. (Right now, children-changed and text-changed events are emitted and Orca has to play "guess if this is a live region which should be presented, or just a DOM mutation.")