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

{
    int64_t nTime = GetSystemTimeInSeconds();
    if (nTime - pnode->nTimeConnected > m_peer_connect_timeout)
    {
        if (pnode->nLastRecv == 0 || pnode->nLastSend == 0)
        {
            LogPrint(BCLog::NET, "socket no message in first %i seconds, %d %d from %d\n", m_peer_connect_timeout, pnode->nLastRecv != 0, pnode->nLastSend != 0, pnode->GetId());
            pnode->fDisconnect = true;
        }
        else if (nTime - pnode->nLastSend > TIMEOUT_INTERVAL)
        {
            LogPrintf("socket sending timeout: %is\n", nTime - pnode->nLastSend);
            pnode->fDisconnect = true;
        }
        else if (nTime - pnode->nLastRecv > (pnode->GetCommonVersion() > BIP0031_VERSION ? TIMEOUT_INTERVAL : 90*60))
        {
            LogPrintf("socket receive timeout: %is\n", nTime - pnode->nLastRecv);
            pnode->fDisconnect = true;