Create a method to for Job Class instance removal

Why

As originally noted in Clarify Sidekiq Job Class and Jobs Removal Proc... (#377742 - closed), when we're cleaning up Job Classes we no longer want, we want a way to also clear up all instances of a job class from:

1. Its expected queue (FooWorker.queue).
2. The scheduled and retry sets (https://docs.gitlab.com/ee/administration/sidekiq/sidekiq_job_migration.html#future-jobs).

What

• something that can run in post release migration