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.
invs.push_back(CInv(MSG_BLOCK | GetFetchFlags(pfrom), resp.blockhash));
                m_connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::GETDATA, invs));
            } else {
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                MarkBlockAsReceived(resp.blockhash); 
                fBlockRead = true;
                
                
                
                
                
                
                mapBlockSource.emplace(resp.blockhash, std::make_pair(pfrom.GetId(), false));
            }