[Live Agent Handover][Outside Business Hours] Design how to detect and handle this escalation failure.

Currently we can not distinguish between "no agents available" and "oustide of business hours" when an escalation fails for these reasons. 

There was some thought that Business Hours might be handled by the DF bot....  and RC has a business hours feature.......  

Need to make a more definitive design for this case, and send the correct event. 