When the consuming application or product is ready to process its operations, it
can use Shoal's new JoinedAndReady reporting facility to let group members know
of this state.
The converse state of this situation may be a valuable piece of information for
administrative or monitoring applications.
If the application could not get into the joined and ready state for any reason
(for instance, an application server consuming Shoal could not complete its
startup and failed midway), then such an unready state can be conveyed through a
notification that specifically identifies this state.
Need an appropriate name for such a notification so it is meaningful.