winrt networking does not work when http access is only available via proxy

A machine that only has http access via proxy is not able to make any connections when using the winrt port of Qt. Http proxies usually have "HostNameLookupCapability" set so that the host lookup in Qt is skipped and the connection is made using the host name (the proxy is responsible for the host lookup then). This logic is not implemented for the winrt port though.

UWP APIs work based on host names so we should not connect to a looked up ip address at all but use the host name directly. DNS lookup and proxy handling (also for VPNs) will happen automatically with this approach.