Hide the extensions to the device page when there is no content

[ozmusic]

Environment

• Nautobot version: 1.5.7
• nautobot-bgp-models version: 0.7.0-beta1

Proposed Functionality

Hide the 'BGP Peer Sessions' and 'BGP Routing Instances' boxes on device pages when there are no sessions or routing instances.

Use Case

Servers, PDUs, cable management, and many other devices will not have BGP sessions or instances. Having the empty boxes there clutters the device page, this could be done by checking for the existence of the filtered object before rendering the box, e.g.:

    def right_page(self):
        """Add content to the right side of the Devices detail view."""
        endpoints = PeerEndpoint.objects.filter(
            routing_instance__device=self.context["object"],
        )
        if endpoints:
            return self.render(
                "nautobot_bgp_models/inc/device_peer_endpoints.html",
                extra_context={"endpoints": endpoints},
            )
        else:
            return ""