Managed domain operation response reports server results in an incorrect location

https://community.jboss.org/wiki/FormatOfADetypedOperationResponse says the "server-groups" portion of the response to a multi-server op should be a sibling of "outcome" and "result". Currently it is a child of "result". This is wrong as it makes "server-groups" a reserved word in the response to any operation.

For 7.1.0.Final it will be reported in both locations. In 7.1.1.Final, the AS7-3677 fix will result in it being removed as a child of "result".