To be able to label incoming tor connections as different from normal localhost connections in e.g. `getpeerinfo` and the peers list in the GUI it'd be useful to have them connect on an alternative local-only port. Or even better, a UNIX socket.

For manually set-up hidden services this would have to be configured manually and could add a `hsport` option or such. The external port would still appear as `XXXXXXXXX.onion:8333`, however internally it would redirect to a that port.

In the case of `torcontrol` this would be easy to set up automatically. It could add a new (localhost) binding port automatically and this code would have to be changed:
- https://github.com/bitcoin/bitcoin/blob/master/src/torcontrol.cpp#L441
- https://github.com/bitcoin/bitcoin/blob/master/src/torcontrol.cpp#L477

{
    Init(connOptions);
    {
        LOCK(cs_totalBytesRecv);
        nTotalBytesRecv = 0;
    }
    {
        LOCK(cs_totalBytesSent);
        nTotalBytesSent = 0;
        nMaxOutboundTotalBytesSentInCycle = 0;
        nMaxOutboundCycleStartTime = 0;
    }
    if (fListen && !InitBinds(connOptions.vBinds, connOptions.vWhiteBinds)) {
        if (clientInterface) {
            clientInterface->ThreadSafeMessageBox(
                _("Failed to listen on any port. Use -listen=0 if you want this."),
                "", CClientUIInterface::MSG_ERROR);
        }
        return false;
    }
    for (const auto& strDest : connOptions.vSeedNodes) {
        AddAddrFetch(strDest);
    }
    if (clientInterface) {
        clientInterface->InitMessage(_("Loading P2P addresses...").translated);
    }