Prepare for bypassing GitLab sign in in feature specs
Implements the first two parts of https://gitlab.com/gitlab-org/gitlab-ce/issues/30196#note_31552752
Edited by Robert Speicher
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Implements the first two parts of https://gitlab.com/gitlab-org/gitlab-ce/issues/30196#note_31552752