Create BroadcastEndpoint implementation using WF clustering API

The upgrade to JGroups 4.0 will break the JGroups BroadcastEndpoint implementation in ActiveMQ Artemis (which uses JGroups 3.x). JGroups is only used to broadcast/receive a byte[] to the cluster. This can be easily implemented using the WildFly clustering API. Such an implementation will simplify the transition to JGroups 4.0 and future-proof WildFly from any new API breakage as well as abstract away concepts like fork channels, etc.