[TEST] Added LongGCDisruption and a test simulating GC on master nodes
Also rename DiscoveryWithNetworkFailuresTests to DiscoveryWithServiceDisruptions which better suites what we do.
Discovery: Added cluster version and master node to the nodes fault detecting ping request

The cluster state version allows resolving the case where a old master node become unresponsive and later wakes up and pings all the nodes in the cluster, allowing the newly elected master to decide whether it should step down or ask the old master to rejoin.