- TabsList has been removing toolbarbuttons (not their parent toolbaritems) and also removing .all-tabs-group-button elements created by GroupsList. Making sure that TabsList only clears group-related toolbaritems in its own menu view
- do some additional waiting/all tabs menu refreshing in the browser_tab_manager_groups tests to make results more consistent
Differential Revision: https://phabricator.services.mozilla.com/D243822