Allow Chests to Be Attached to Happy Ghasts

With the new Happy Ghast it would be great if players could attach chests to it, similar to donkeys or llamas. This would allow players to transport blocks and items while flying, especially useful in the Nether or during long-distance travel. If you're standing on the Ghast and building, you could access blocks directly from the chest, making it easier to build in the air or across large gaps without constantly opening your inventory.