New backup feature raise event on completion

Could the new backup feature for core raise an event when the backup completes? It would be really useful to know when a backup completes and if it was successful.

The event data should also include the filename.
It looks like someone already implemented this in a supervisor fork, but it was never added upstream. backups/manager: Emit supervisor update events on backup start/end · 3v1n0/ha-supervisor@d385b6b · GitHub