ISPN-4736 Implement efficient size operation in Hot Rod 2.0

* For local or replicated caches, it queries the cache itself to
calculate size of cache. Persistent stores are taken into account.
* For distributed caches, it uses M/R tasks to get the number of
total keys in the cluster.
ISPN-4470 Remove tabs and fix other formatting issues
ISPN-4470 Implement RemoteCache.size() w/ new Hot Rod size command

* Implement RemoteCache.size() using new Hot Rod 2.0 size operation.
* This provides an accurate element count that works with distributed
caches and persistent stores.