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.
{
                LOCK(cs_main);
                mapBlockSource.emplace(pblock->GetHash(), std::make_pair(pfrom.GetId(), false));
            }
            bool fNewBlock = false;
            
            
            
            
            
            
            
            
            
            m_chainman.ProcessNewBlock(m_chainparams, pblock, true, &fNewBlock);
            if (fNewBlock) {
                pfrom.nLastBlockTime = GetTime();
            } else {
                LOCK(cs_main);
                mapBlockSource.erase(pblock->GetHash());
            }
            LOCK(cs_main); 
            if (pindex->IsValid(BLOCK_VALID_TRANSACTIONS)) {
                
                
                
                
                MarkBlockAsReceived(pblock->GetHash());
            }
        }