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

{
    if (b_conn)
        bufferevent_free(b_conn);
    b_conn = nullptr;
}
bool TorControlConnection::Command(const std::string &cmd, const ReplyHandlerCB& reply_handler)
{
    if (!b_conn)
        return false;
    struct evbuffer *buf = bufferevent_get_output(b_conn);
    if (!buf)
        return false;
    evbuffer_add(buf, cmd.data(), cmd.size());
    evbuffer_add(buf, "\r\n", 2);
    reply_handlers.push_back(reply_handler);
    return true;
}
/* Split reply line in the form 'AUTH METHODS=...' into a type
 * 'AUTH' and arguments 'METHODS=...'.
 * Grammar is implicitly defined in https://spec.torproject.org/control-spec by
 * the server reply formats for PROTOCOLINFO (S3.21) and AUTHCHALLENGE (S3.24).
 */
std::pair<std::string,std::string> SplitTorReplyLine(const std::string &s)