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.
pnode->CloseSocketDisconnect();
                
                pnode->Release();
                vNodesDisconnected.push_back(pnode);
            }
        }
    }
    {
        
        std::list<CNode*> vNodesDisconnectedCopy = vNodesDisconnected;
        for (CNode* pnode : vNodesDisconnectedCopy)
        {
            
            if (pnode->GetRefCount() <= 0) {
                bool fDelete = false;
                {
                    TRY_LOCK(pnode->cs_vSend, lockSend);
                    if (lockSend) {
                        fDelete = true;
                    }
                }
                if (fDelete) {
                    vNodesDisconnected.remove(pnode);
                    DeleteNode(pnode);
                }
            }
        }
    }
}
void CConnman::NotifyNumConnectionsChanged()