Allow operator shelves to contain grouped apps.

r? @diox @ngokevin 

I have a few tests failing locally, but I'm pretty sure it's an ES misconfiguration and not an actual problem. I'll see what CI thinks.
Yeah, 0 is one group which points to a name in group_names. That would make sense...but I don't think we're going to change it at this point. It's probably how the data is posted  to our endpoints.