[WFLY-3978] - PicketLink EAP 6.4 Issues

[BZ-1155492] - PicketLink Subsystem dissapears after removing last federation after reload.
[BZ-1155501] - Adding empty PicketLink Subsystem causes disappearance of another PicketLink Subsystem
[BZ-1151002] - Class-name/code attributes causes conflicts in PicketLink Federation subsystem.
[BZ-1150639] - Class-name/code attributes causes conflicts in PicketLink IDM subsystem.
[BZ-1151230] - Validation is not invoked when changing existing partition manager configuration in IDM subsystem.