Consider separating ActionCable and SideKiq redis instances

[ajkiessl]

SideKiq recommends using different redis instances for different services (rather than one instance with separate namespaces). There are a number of reasons not to share redis instances, but one major reason is the possibility of key collisions. We are using ActionCable and SideKiq with a single redis instance. While this isn't causing any issues right now — and I wouldn't consider this a high priority — it might be worth separating these out for security and longevity. I believe this would require some alterations to the scholarsphere-config helm charts.

We've done this with ETDA to separate our SideKiq queues amongst partners. So, that could be a good reference.