ISPN-4490 Members can miss the rebalance cancellation on coordinator change

Simulate the rebalance cancellation in StateTransferManagerImpl.
ISPN-4496 EncryptProtocolIT shouldn't check passwords via JMX
Replace ignore tests with empty test to avoid false alarms
ISPN-3743

Ignore some of the errors that can be thrown by a node while stopping:
IllegalStateException and NullPointerException.