feat: Add SMTP integration scenario
Launches a MailHog instance and injects configuration to gitlab to use it as smtp delivery server
Related https://gitlab.com/gitlab-org/gitlab/merge_requests/20675
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Launches a MailHog instance and injects configuration to gitlab to use it as smtp delivery server
Related https://gitlab.com/gitlab-org/gitlab/merge_requests/20675