[WFLY-3349] Synchronization of cosmetic schema changes with EAP.

The purpose of this commit is to make it easier to verify that the EAP and WildFly schemas are actually in synch.
Merge pull request #6267 from darranl/WFLY-3349

[WFLY-3349] Synchronization of cosmetic schema changes with EAP.
[WFLY-2741] Single process management operation timeouts
Use shared utility for managing test extension module
[WFLY-3058] Expose actively executing mgmt ops as management resources
[WFLY-3090] Prevent mgmt op cancellation resulting in closing intra-process connections
[WFLY-3091] Fix propagation of mgmt op cancellation to server update tasks
Tests of the above and of WFLY-3058
[WFLY-3058] Add convenience ops to find/cancel non-progressing ops