Visualize connectivity to undiscoverable Google VPC peering endpoints

NetBrain currently cannot represent connectivity to a Google Cloud VPC peering endpoint when that peered VPC is not discoverable or accessible within the domain, leaving the relationship absent from topology maps. This enhancement would allow NetBrain to display a placeholder or logical representation of the peering connection to the unknown VPC, even when the peer device itself cannot be discovered. Customers operating multi-VPC or multi-account GCP environments would gain more complete topology visibility and a clearer understanding of cross-VPC connectivity without requiring full access to every peered environment.