CommandClasses should be stored/unique per endpoint.

[Fishwaldo]

For MultiChannel devices - we should store each supported CC based on the endpoint, rather than a single list tied to the node. Otherwise we could run into issues where 2 different endpoints have different configurations/settings per CC.

Also - If a CC is both a Controlling and Controlled CC (eg, comes after the 0xef list in the NIF or MultiChannelCapabilityReports etc) then we get confused.