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

BF_NONE         = 0,
    BF_EXPLICIT     = (1U << 0),
    BF_REPORT_ERROR = (1U << 1),
};
static const uint64_t SELECT_TIMEOUT_MILLISECONDS = 50;
const std::string NET_MESSAGE_COMMAND_OTHER = "*other*";
static const uint64_t RANDOMIZER_ID_NETGROUP = 0x6c0edd8036ef4036ULL; 
static const uint64_t RANDOMIZER_ID_LOCALHOSTNONCE = 0xd93e69e2bbfa5735ULL; 
static const uint64_t RANDOMIZER_ID_ADDRCACHE = 0x1cf2e4ddd306dda9ULL; 
bool fDiscover = true;
bool fListen = true;
bool g_relay_txes = !DEFAULT_BLOCKSONLY;
RecursiveMutex cs_mapLocalHost;
std::map<CNetAddr, LocalServiceInfo> mapLocalHost GUARDED_BY(cs_mapLocalHost);
static bool vfLimited[NET_MAX] GUARDED_BY(cs_mapLocalHost) = {};
std::string strSubVersion;
void CConnman::AddAddrFetch(const std::string& strDest)
{
    LOCK(m_addr_fetches_mutex);
    m_addr_fetches.push_back(strDest);
}
uint16_t GetListenPort()