addPortMapping
suspend fun addPortMapping(client: HttpClient, controlUrl: String, externalPort: Int, internalPort: Int, internalClient: String, tcp: Boolean, leaseSeconds: Int = DEFAULT_LEASE_SECONDS, description: String = "KiteTorrent", serviceType: String = WAN_IP_SERVICE): Boolean
POST an AddPortMapping SOAP action to the gateway's control URL. Returns true on success.