`REMOVED` Event Should Be Fired For Only BlockState Removals

[Kneelawk]

The Issue

Currently the REMOVED event is fired for all BlockState changes, not just when the MultipartBlock is removed. This means that updating a part container's properties from a part's onAdded method will result in it receiving the REMOVED event immediately.

Potential Solution

A potential solution would be to check that the new state is not a multipart block in MultipartBlock.onStateReplaced.