For every peer expose through `getpeerinfo` RPC whether or not we selected them as HB peers, and whether or not they selected us as HB peers.

Suggestion by @gmaxwell.
throw JSONRPCError(RPC_DATABASE_ERROR, "Error: Ban database not loaded");
    }
    CSubNet subNet;
    CNetAddr netAddr;
    bool isSubnet = false;
    if (request.params[0].get_str().find('/') != std::string::npos)
        isSubnet = true;
    if (!isSubnet) {
        CNetAddr resolved;
        LookupHost(request.params[0].get_str(), resolved, false);
        netAddr = resolved;
    }
    else
        LookupSubNet(request.params[0].get_str(), subNet);
    if (! (isSubnet ? subNet.IsValid() : netAddr.IsValid()) )
        throw JSONRPCError(RPC_CLIENT_INVALID_IP_OR_SUBNET, "Error: Invalid IP/Subnet");
    if (strCommand == "add")
    {
        if (isSubnet ? node.banman->IsBanned(subNet) : node.banman->IsBanned(netAddr)) {
            throw JSONRPCError(RPC_CLIENT_NODE_ALREADY_ADDED, "Error: IP/Subnet already banned");
        }
        int64_t banTime = 0; 
        if (!request.params[2].isNull())
            banTime = request.params[2].get_int64();
        bool absolute = false;
        if (request.params[3].isTrue())
            absolute = true;
        if (isSubnet) {
            node.banman->Ban(subNet, banTime, absolute);
            if (node.connman) {