Display empty deployment configs and latest deployments

[smarterclayton]

The console UI should show at least the most recent deployment when scaled to 0 (so you know a deployment existed), and probably should show recent deployments (<N-1) for a brief period of time before hiding them. There should probably be a way in the UI to see older deployments. Eventually we'll want to have a scale control on 0 deployments.

Empty RCs not in deployment configs should always be shown.

[jwforres]

@fabianofranz something to consider while you are looking at deployment stuff

[fabianofranz]

@jwforres ok, I'll have that in mind. ATM we just blindly display every deployment attached to the given dc, and deployments without a dc in a separate section, without any smarter handling about the history or scale.

[jwforres]

This is partially fixed by #4726

need to look at what we want to show in the overview in some of these cases

[spadgett]

@jwforres So this is what happens when you show the donut chart with no data... The ring disappears. I feel like we could do better, but I'm not sure what. Thoughts?

[spadgett]

We could add a light gray ring with a custom tooltip, but that's what we use for pending today.