Revert "Merge branch '2001-related-issues' into 'master'"
Revert https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1719 as the frontend isn't ready, and we therefore don't want this in 9.3.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Revert https://gitlab.com/gitlab-org/gitlab-ee/merge_requests/1719 as the frontend isn't ready, and we therefore don't want this in 9.3.