Server results on domain ops are reported as children of the response's "result"

https://community.jboss.org/wiki/FormatOfADetypedOperationResponse says the "server-groups" data structure describing responses to a domain op should be a sibling of "outcome" and "result". Prior to 7.1.0.Final they are being reported as a child of "result", not a sibling. The final AS7-2907 fix for 7.1.0.Final will result in them being reported in both places, with the "child of 'result'" reporting maintained only to avoid breaking the console. Once AS7-3676 is completed, the reporting as "child of 'result'" should be removed.