Add a wait_for_ajax call to ensure Todos page cleans up properly
Potentially fixes intermittent failures such as https://gitlab.com/gitlab-org/gitlab-ce/builds/13484375
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Potentially fixes intermittent failures such as https://gitlab.com/gitlab-org/gitlab-ce/builds/13484375