Sidekiq documentation says 'Sidekiq is not designed to work well with dozens of queues.'. Having the amount of queues we have at the moment brings no anyway.
Closes#5571
* add a class for checking pod connectivity
* extend pod model to handle new functionality
* add an admin frontend to list pods and re-trigger checks manually
* add a daily worker to run through all the pods
* add unit tests for most of the new code
