[Tests] verifyThreadNames should account for new threads of shared cluster

The verifyThreadNames starts a node and checks that all new threads on the JVM are properly named. The current test uses the name of the new node which sometimes fails because our shared cluster spawns a new thread which is properly named but for not for the new name.

The commits relaxes the requirement of the test and on verify the threads are properly named (but not necessarily of the new node)