UpnpSearchAsync searches for devices matching the given search target.
UpnpSearchAsync searches for devices matching the given search target. The function returns immediately and the SDK calls the default callback function, registered during the UpnpRegisterClient call, for each matching root device, device, or service. The application specifies the search type by the Target parameter.Note that there is no way for the SDK to distinguish which client instance issued a particular search. Therefore, the client can get search callbacks that do not match the original criteria of the search. Also, the application will receive multiple callbacks for each search.