ISPN-4873 Statetransfer thread pool deadlock

* Update LargeClusterStressTest to create a large number of caches
* Make StateRequestCommand implement TopologyAffectedCommand
ISPN-4941 Re-enabling rebalancing should not start a rebalance for a cache
in degraded mode
ISPN-3645 StateTransferLargeObjectTest hangs randomly

Add a more focused and reliable test: RemoteGetStressTest.