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_totalBytesSent);
    nMaxOutboundLimit = limit;
}
uint64_t CConnman::GetMaxOutboundTarget()
{
    LOCK(cs_totalBytesSent);
    return nMaxOutboundLimit;
}
uint64_t CConnman::GetMaxOutboundTimeframe()
{
    LOCK(cs_totalBytesSent);
    return nMaxOutboundTimeframe;
}
uint64_t CConnman::GetMaxOutboundTimeLeftInCycle()
{
    LOCK(cs_totalBytesSent);
    if (nMaxOutboundLimit == 0)
        return 0;
    if (nMaxOutboundCycleStartTime == 0)
        return nMaxOutboundTimeframe;
    uint64_t cycleEndTime = nMaxOutboundCycleStartTime + nMaxOutboundTimeframe;
    uint64_t now = GetTime();
    return (cycleEndTime < now) ? 0 : cycleEndTime - GetTime();
}
void CConnman::SetMaxOutboundTimeframe(uint64_t timeframe)