MODE-2242 Added back 'modeshape-security' security domain, though it now uses existing 'ApplicationRealm' to manage users/roles

Changed back to a "`modeshape-security`" security domain that reuses the  existing "`ApplicationRealm`" security realm for authentication. So users with ModeShape roles are still added via the Wildfly (and EAP) `add-user.sh` script (resulting in encrypted passwords).