Add getTotalSize() for Infinispan 5.2 and greater

Use a distributed executor to get the local cache size of each node,
then determine the total size based on the clustering mode and cluster
size.

Note: The accuracy of results with passivation enabled on Infinispan
versions less than 6 is not guaranteed.
Remove references to maxCollector and fix RandomDataStage

maxCollector was removed in Infinispan 7
RandomDataStage should not pick a word with length = 0
Also log word counts across the cluster
Sync plugin dependency versions with Infinispan and JDG