Support retrieving all known external groups from NoteDb
Support retrieving all known external groups from NoteDb

Change-Id: Ife65df6659f4ec7be0128d90591c5c3c03ea201b

WANdisco/gerrit,WANdisco/gerrit,WANdisco/gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,WANdisco/gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit,qtproject/qtqa-gerrit,GerritCodeReview/gerrit,WANdisco/gerrit,GerritCodeReview/gerrit,qtproject/qtqa-gerrit