Include metadata in Sidekiq jobs scheduled from Cron jobs

In #9 (closed) we've added metadata about sidekiq jobs based on the controller/api endpoint that scheduled the jobs.

We should also provide this information when a job is scheduled as a cron job (workers that include CronjobQueue), and the workers those schedule. This will probably be a manual process for these jobs, so we'll need to do it for existing workers, and add a rubocop to make sure it's done for all workers added in the future.

The context for these workers is detirmined by the arguments they were scheduled with (project_id, current_user_id, mirror_user_id, ...) so the client middleware will need to query for the right resources to add them to the job in the normalized format.