Consumables refactor (#1796)

* Removed broken EntityEatEvents - these don't fit the pattern since they only apply to Human entities anyway. PlayerItemConsumeEvent and PlayerInteractEvent can be used for cancellation purposes, and plugins can do custom stuff without mess.

* Restrict item consuming to Living entities only

* Added FoodSource->requiresHunger()

* Only items implementing the Consumable interface can now be consumed.

* The effects from consuming items are now generic-ized by way of the Living->consume() function. This is overridden in Human to allow applying food and hunger.

* Fixed the hardcoded mess for buckets

src/pocketmine/item/FoodSource.php

@@ -23,9 +23,18 @@ declare(strict_types=1);
 
 namespace pocketmine\item;
 
+/**
+ * Interface implemented by objects that can be consumed by players, giving them food and saturation.
+ */
 interface FoodSource extends Consumable{
 
 	public function getFoodRestore() : int;
 
 	public function getSaturationRestore() : float;
+
+	/**
+	 * Returns whether a Human eating this FoodSource must have a non-full hunger bar.
+	 * @return bool
+	 */
+	public function requiresHunger() : bool;
 }