MultiBlock Support

[RedRelay]

Currently multiblocks like doors or bed will be healed part by part.
Improve code for supporting multi block.

Instead of using a BlockSnapshot in a HealableEntry, I have to create a wrapper HealableBlock.
HealableBlock must be a interface with restore function and should be serializable.
I have to create an other registry to register HealableBlock builders

[RedRelay]

With no multiblock support if there is a block update when multiblock are splited, it drop