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);
    CNodeState *state = State(node);
    if (state) state->m_last_block_announcement = time_in_seconds;
}
void PeerManager::InitializeNode(CNode *pnode) {
    CAddress addr = pnode->addr;
    std::string addrName = pnode->GetAddrName();
    NodeId nodeid = pnode->GetId();
    {
        LOCK(cs_main);
        mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, pnode->IsInboundConn(), pnode->IsManualConn()));
        assert(m_txrequest.Count(nodeid) == 0);
    }
    {
        PeerRef peer = std::make_shared<Peer>(nodeid);
        LOCK(m_peer_mutex);
        m_peer_map.emplace_hint(m_peer_map.end(), nodeid, std::move(peer));
    }
    if (!pnode->IsInboundConn()) {
        PushNodeVersion(*pnode, GetTime());
    }
}
void PeerManager::ReattemptInitialBroadcast(CScheduler& scheduler) const