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.
bool pingSend = false;
    if (pto->fPingQueued) {
        
        pingSend = true;
    }
    if (pto->nPingNonceSent == 0 && pto->m_ping_start.load() + PING_INTERVAL < GetTime<std::chrono::microseconds>()) {
        
        pingSend = true;
    }
    if (pingSend) {
        uint64_t nonce = 0;
        while (nonce == 0) {
            GetRandBytes((unsigned char*)&nonce, sizeof(nonce));
        }
        pto->fPingQueued = false;
        pto->m_ping_start = GetTime<std::chrono::microseconds>();
        if (pto->GetCommonVersion() > BIP0031_VERSION) {
            pto->nPingNonceSent = nonce;
            m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING, nonce));
        } else {
            
            pto->nPingNonceSent = 0;
            m_connman.PushMessage(pto, msgMaker.Make(NetMsgType::PING));
        }
    }
    {
        LOCK(cs_main);
        CNodeState &state = *State(pto->GetId());