Custom view for single Gateway resource

[R-Lawton]

What/WHY

Enhance the current view for single Gateway resources to allow users to manage gateways, view associated HTTPRoutes and help troubleshoot what might be wrong with a gateway.

Tasks:

• Show the associated resources like HTTPRoutes similar to what we do for gateway and the policies tab.

• Editing a gateway should use our custom form view

Requires work from UXD to come up with designs