[Feature] Pre- & Post- Transformation Methods

[Kneelawk]

The Issue

Currently, parts that must coordinate with each other when rotating (switching places within a block, storing relative position information, etc.) have no way of knowing when other parts will be transformed. In my specific use-case, parts store information on which part is in which part of a block, information that must be recalculated if these parts change places.

Potential Solution

A potential solution would be to have pre- and post- methods called before and after all parts are transformed. This would allow me to recalculate parts position information once all parts are in their final places.