TrappedChest's MaterialData should be org.bukkit.material.Chest

It's confusing that TrappedChests don't have `org.material.Chest` as `MaterialData`.
That is IMO a logical mistake and TrappedChests' facing direction can't be changed (by plugins).

This PR changes this without breaking any plugins/sever implementations/etc.

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*Edited by turt2live*

**Related links:**
- Glowstone: GlowstoneMC/Glowstone#358
  - Glowstone PR is not required for operation/implementation