Improve underlay path visualization for Arista devices

NetBrain currently does not present the underlay path for Arista devices in a clear, user-friendly manner within path calculation results, making it difficult for users to interpret the underlying network structure. This enhancement would improve the map and path trace rendering to clearly display the underlay path segments associated with Arista devices, with a presentation consistent with other supported path elements. Customers troubleshooting Arista environments with overlay and underlay layers would gain clearer visibility into the underlying path, reducing the manual effort needed to interpret network topology during troubleshooting.