WIP: Add rubocop-thread_safety checks
This is important not only to prevent Sidekiq issues, but also to prepare support for a multithreaded app server.
First step to addressing #3592 (moved)
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
This is important not only to prevent Sidekiq issues, but also to prepare support for a multithreaded app server.
First step to addressing #3592 (moved)