[ASTERIXDB-2107][CLUS] Prevent Invalid UNUSABLE State in Dynamic Topology - user model changes: no - storage format changes: no - interface changes: yes Renamed IClusterStateManager add/Remove NCConfig methods to notifyNode join/failure.
Details: - Mark node as participant when it completes its startup and not when it joins the cluster. - Allow partitions to be added with pending activation state. - Remove the use of static MetadataProperties for reporting number of nodes. - Add test cases.