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

{
    std::map<std::string,std::string> mapping;
    size_t ptr=0;
    while (ptr < s.size()) {
        std::string key, value;
        while (ptr < s.size() && s[ptr] != '=' && s[ptr] != ' ') {
            key.push_back(s[ptr]);
            ++ptr;
        }
        if (ptr == s.size()) 
            return std::map<std::string,std::string>();
        if (s[ptr] == ' ') 
            break;
        ++ptr; 
        if (ptr < s.size() && s[ptr] == '"') { 
            ++ptr; 
            bool escape_next = false;
            while (ptr < s.size() && (escape_next || s[ptr] != '"')) {
                
                escape_next = (s[ptr] == '\\' && !escape_next);
                value.push_back(s[ptr]);
                ++ptr;
            }
            if (ptr == s.size()) 
                return std::map<std::string,std::string>();
            ++ptr; 
            /**
             * Unescape value. Per https://spec.torproject.org/control-spec section 2.1.1: