Allow use of BlockEntityType for registering components on block entities. #63

Currently CCA uses the block entity class to identify a block entity for registering components. However this has some issues due to limiting the types of supported block entities.

In one of my mods, I have moved to a builder system to create a block entity and it's corresponding blocks and items so I do not have a mess registering stuff. Simply I have two block entity implementations, one with an inventory and one without. This is preferable to me atleast since I can avoid having 20+ classes just for each type of block entity when the changes are anything but visual changes or changes in ticking logic which I can easily abstract.

A solution to this would be adding a parallel registration pipeline which allows for use of block entity types for attaching components to block entity instances.