Merge pull request #19569 from nextcloud/enh/noid/restrict-user-enumeration-to-groups

apps/dav/lib/CardDAV/SystemAddressbook.php

apps/dav/lib/Connector/Sabre/Principal.php

apps/dav/tests/unit/Connector/Sabre/PrincipalTest.php

apps/files_sharing/lib/Controller/ShareesAPIController.php

...les_sharing/tests/Controller/ShareesAPIControllerTest.php

apps/settings/js/admin.js

apps/settings/lib/Settings/Admin/Sharing.php

apps/settings/templates/settings/admin/sharing.php

apps/settings/tests/Settings/Admin/SharingTest.php

lib/private/Collaboration/Collaborators/GroupPlugin.php

lib/private/Collaboration/Collaborators/MailPlugin.php

lib/private/Collaboration/Collaborators/UserPlugin.php

lib/private/Contacts/ContactsMenu/ContactsStore.php

lib/private/Share20/Manager.php

lib/public/Share/IManager.php

tests/lib/Collaboration/Collaborators/UserPluginTest.php

tests/lib/Contacts/ContactsMenu/ContactsStoreTest.php