Void Pocket Blocks

What do I want: A block, that can only be manually farmed by players, that allows for blocks to be placed while still having creative potential

Why do I want it: Like how there is creative potential to break blocks with TNT (That needs the player to manually dig up sand to craft it), I think there should be a way to place blocks that has creative potential and requires some manually labour on the player's part to keep using it.

How I think it should be implemented:
- Void Pocket Block clusters rarely generate on top of the void in the end
- Void Pocket Blocks won't drop an item if blown up by TNT or broken by a wither
- Void Pocket Blocks will only drop an item if broken by a golden pickaxe
- If a Void Pocket Block is thrown into the void, a new cluster will generate
- If a Void Pocket Block is thrown onto a block, a Void Pocket Block will replace the block
- If an block is dropped onto a Void Pocket Block, the block will replace the Void Pocket Block