Change Sidekiq queues to critical, default and low only. For efficiency

[gustavosobral]

What

It creates three queues (critical, default, and low) and assign all the workers to it.

From Sidekiq documentation:

I don't recommend having more than a handful of queues. Lots of queues makes for a more complex system and Sidekiq Pro cannot reliably handle multiple queues without polling. M Sidekiq Pro processes polling N queues means O(M*N) operations per second slamming Redis. https://github.com/mperham/sidekiq/wiki/Advanced-Options#queues

Closes #1381

[andrewbredow]

@JessRudder Adding you as reviewer because I think this is moda-focused. Feel free to redirect if not.