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/Bucket.php

@@ -27,13 +27,14 @@ use pocketmine\block\Air;
 use pocketmine\block\Block;
 use pocketmine\block\BlockFactory;
 use pocketmine\block\Liquid;
+use pocketmine\entity\Living;
 use pocketmine\event\player\PlayerBucketEmptyEvent;
 use pocketmine\event\player\PlayerBucketFillEvent;
 use pocketmine\level\Level;
 use pocketmine\math\Vector3;
 use pocketmine\Player;
 
-class Bucket extends Item{
+class Bucket extends Item implements Consumable{
 	public function __construct(int $meta = 0){
 		parent::__construct(self::BUCKET, $meta, "Bucket");
 	}
@@ -85,4 +86,20 @@ class Bucket extends Item{
 
 		return false;
 	}
+
+	public function getResidue(){
+		return ItemFactory::get(Item::BUCKET, 0, 1);
+	}
+
+	public function getAdditionalEffects() : array{
+		return [];
+	}
+
+	public function canBeConsumed() : bool{
+		return $this->meta === 1; //Milk
+	}
+
+	public function onConsume(Living $consumer){
+		$consumer->removeAllEffects();
+	}
 }