CloudGenix SD-WAN VPN tunnel discovery via vendor REST API

NetBrain discovery does not consistently identify all VPN tunnels for SD-WAN devices from certain vendors, which can leave some devices unreachable for CLI-based access even though they are configured with valid credentials. This enhancement would extend discovery to use the vendor's REST API to retrieve tunnel and device relationship data directly from the SD-WAN controller, filling gaps left by traditional discovery methods. Customers running SD-WAN environments would gain more complete and reliable topology and device visibility, reducing troubleshooting delays caused by incomplete discovery.