Add getDrops to BlockState and isPreferredTool to BlockData

[MelnCat]

This adds the getDrops and isPreferredTool methods to BlockState, as only Block had these methods before. It was not possible to get the drops of a BlockState before. The getDrops and isPreferredTool methods in Block actually only used the blockState, so this change was mostly just copied from Block.

[MelnCat]

Requested changes added:

• Inlined imports
• Made the return type of getDrops immutable
• Removed the private isPreferredTool