ISPN-4519 Prepare should be broadcasted to entire cluster in replicated mode

Command should be sent to null even if not all caches are members
ISPN-4517 RollbackCommands should ignore leavers
ISPN-4484 fix caused unnecessary InterruptedExceptions

When state transfer is over, the response to the last StateResponseCommand
could reach the provider node after the CH_UPDATE from the coordinator.

If that happens, no data is lost, but the OutboundTransferTask thread is
interrupted and it logs the InterruptedException stack trace.
ISPN-4552 Upgrade H2 driver to 1.4.180
ISPN-4550 JpaStoreOOMETest.testProcessClear always fails

* store the data in disk to avoid OOME
ISPN-1951 Use MERGE3 in the default UDP configuration

TEST_PING needed some changes, as MERGE3 doesn't trigger Discovery.findMembers()
Smaller timer pool and queue.
Still causes lots of failures.