Fix background jobs not using locks like they are supposed to (#13361)

Also:

- Fix locks not being removed when jobs go to the dead job queue
- Add UI for managing locks to the Sidekiq dashboard
- Remove unused Sidekiq workers

Fix #13349

app/workers/resolve_account_worker.rb

@@ -3,7 +3,7 @@
 class ResolveAccountWorker
   include Sidekiq::Worker
 
-  sidekiq_options queue: 'pull', unique: :until_executed
+  sidekiq_options queue: 'pull', lock: :until_executed
 
   def perform(uri)
     ResolveAccountService.new.call(uri)