[MM-56904] Reduce the number of api requests made to fetch user information for GMs on page load (#27149)

* use new endpoint to fetch group members

server/public/model/migration.go

@@ -47,5 +47,6 @@ const (
 	MigrationKeyAddIPFilteringPermissions              = "add_ip_filtering_permissions"
 	MigrationKeyAddOutgoingOAuthConnectionsPermissions = "add_outgoing_oauth_connections_permissions"
 	MigrationKeyAddChannelBookmarksPermissions         = "add_channel_bookmarks_permissions"
+	MigrationKeyDeleteDmsPreferences                   = "delete_dms_preferences_migration"
 	MigrationKeyAddManageJobAncillaryPermissions       = "add_manage_jobs_ancillary_permissions"
 )