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 (net == NET_UNROUTABLE || net == NET_INTERNAL)
        return;
    LOCK(cs_mapLocalHost);
    vfLimited[net] = !reachable;
}
bool IsReachable(enum Network net)
{
    LOCK(cs_mapLocalHost);
    return !vfLimited[net];
}
bool IsReachable(const CNetAddr &addr)
{
    return IsReachable(addr.GetNetwork());
}
bool SeenLocal(const CService& addr)
{
    {
        LOCK(cs_mapLocalHost);
        if (mapLocalHost.count(addr) == 0)
            return false;
        mapLocalHost[addr].nScore++;
    }
    return true;
}
bool IsLocal(const CService& addr)