[Dev UI] Better UX for nested custom objects

[shrutip90]

Currently we render them as flattened objects in the config panel, but these names are not easy to understand. We need better UX designs for representing nested objects.

[MichaelDoyle]

Is this all set? Or changes still needed here.

[mjchristy]

I think we're good on this - any tickets at this point would be a lot more specific. Thanks, Mike!