Add block dig time recalculation

[zardoy]

It's pretty common to have conditions for calculating dig time to be changed. The vanilla behavior is to just change the digging speed without resetting the digging progress, thus an event should be added.

For things like interactive clients (p viewer) this is super important. For example, when you dig down, the dig time is calculated taking into account the fact you are currently in the air but it doesn't get changed when you fall to the ground which makes digging time desync.

[zardoy]

For things like interactive clients (p viewer) this is super important

I think I'm going to change the logic in prismarine web client so it ignores dig time and instead uses block_break_animation packet to update the progress (blockBreakProgressObserved event). and blockBreakProgressEnd to actually update the block (remove from the world). I guess this is more correct behavior that should also be used in mineflayer as the server can simply cancel block breakage for some reason