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.
if (!peer->m_getdata_requests.empty()) return true;
    }
    {
        LOCK(g_cs_orphans);
        if (!peer->m_orphan_work_set.empty()) return true;
    }
    
    if (pfrom->fPauseSend)
        return false;
    std::list<CNetMessage> msgs;
    {
        LOCK(pfrom->cs_vProcessMsg);
        if (pfrom->vProcessMsg.empty())
            return false;
        
        msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin());
        pfrom->nProcessQueueSize -= msgs.front().m_raw_message_size;
        pfrom->fPauseRecv = pfrom->nProcessQueueSize > m_connman.GetReceiveFloodSize();
        fMoreWork = !pfrom->vProcessMsg.empty();
    }
    CNetMessage& msg(msgs.front());
    msg.SetVersion(pfrom->GetCommonVersion());
    const std::string& msg_type = msg.m_command;
    
    unsigned int nMessageSize = msg.m_message_size;
    try {
        ProcessMessage(*pfrom, msg_type, msg.m_recv, msg.m_time, interruptMsgProc);
        if (interruptMsgProc) return false;
        {
            LOCK(peer->m_getdata_requests_mutex);