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.
{
    auto txinfo = mempool.info(gtxid);
    if (txinfo.tx) {
        
        
        
        if ((mempool_req.count() && txinfo.m_time <= mempool_req) || txinfo.m_time <= now - UNCONDITIONAL_RELAY_DELAY) {
            return std::move(txinfo.tx);
        }
    }
    {
        LOCK(cs_main);
        
        if (State(peer.GetId())->m_recently_announced_invs.contains(gtxid.GetHash())) {
            
            if (txinfo.tx) return std::move(txinfo.tx);
            
            auto mi = mapRelay.find(gtxid.GetHash());