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.
connman.PushMessage(&pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::BLOCK, *pblock));
            } else if (inv.IsMsgWitnessBlk()) {
                connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::BLOCK, *pblock));
            } else if (inv.IsMsgFilteredBlk()) {
                bool sendMerkleBlock = false;
                CMerkleBlock merkleBlock;
                if (pfrom.m_tx_relay != nullptr) {
                    LOCK(pfrom.m_tx_relay->cs_filter);
                    if (pfrom.m_tx_relay->pfilter) {
                        sendMerkleBlock = true;
                        merkleBlock = CMerkleBlock(*pblock, *pfrom.m_tx_relay->pfilter);
                    }
                }
                if (sendMerkleBlock) {
                    connman.PushMessage(&pfrom, msgMaker.Make(NetMsgType::MERKLEBLOCK, merkleBlock));
                    
                    
                    
                    
                    
                    
                    typedef std::pair<unsigned int, uint256> PairType;
                    for (PairType& pair : merkleBlock.vMatchedTxn)
                        connman.PushMessage(&pfrom, msgMaker.Make(SERIALIZE_TRANSACTION_NO_WITNESS, NetMsgType::TX, *pblock->vtx[pair.first]));
                }
                
                    
            } else if (inv.IsMsgCmpctBlk()) {