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.
return;
        }
    }
    {
        LOCK(cs_main);
        CNodeState *nodestate = State(pfrom.GetId());
        if (nodestate->nUnconnectingHeaders > 0) {
            LogPrint(BCLog::NET, "peer=%d: resetting nUnconnectingHeaders (%d -> 0)\n", pfrom.GetId(), nodestate->nUnconnectingHeaders);
        }
        nodestate->nUnconnectingHeaders = 0;
        assert(pindexLast);
        UpdateBlockAvailability(pfrom.GetId(), pindexLast->GetBlockHash());
        
        
        
        if (received_new_header && pindexLast->nChainWork > ::ChainActive().Tip()->nChainWork) {
            nodestate->m_last_block_announcement = GetTime();
        }
        if (nCount == MAX_HEADERS_RESULTS) {
            
            
            
            LogPrint(BCLog::NET, "more getheaders (%d) to end to peer=%d (startheight:%d)\n", pindexLast->nHeight, pfrom.GetId(), pfrom.nStartingHeight);
            m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETHEADERS, ::ChainActive().GetLocator(pindexLast), uint256()));
        }
        bool fCanDirectFetch = CanDirectFetch(m_chainparams.GetConsensus());
        
        
        if (fCanDirectFetch && pindexLast->IsValid(BLOCK_VALID_TREE) && ::ChainActive().Tip()->nChainWork <= pindexLast->nChainWork) {
            std::vector<const CBlockIndex*> vToFetch;