Added new block format support for `eosmechanics`

[chamorin]

I'm still missing the code to handle pending_schedule since it's no longer there in the new block format. Because of that:

// If there is no pending schedule, then there is no schedule change
if pending_schedule.is_empty() {
    return Ok(Default::default());
}

will always return empty for map_schedule_change

[YaroShkvorets]

LGTM

[YaroShkvorets]

Actually no, it doesn't produce any schedule changes at all now. Need to find a way a better way to detect schedule change.

[YaroShkvorets]

@DenisCarriere when you have time can you look into it?

[chamorin]

I added a check for pending_schedule, so if it's the new block format it will not take pending_schedule into account. If it's the new block format it will only rely on active_schedule