Implemented coral and coral fans

this implementation is very rough due to having to hack around lots more MCPE bullshit, and currently doesn't allow dynamic coral types; but it's there. We'll clean this up after 1.13 migration is done.

src/block/BaseCoral.php

@@ -0,0 +1,79 @@
+<?php
+
+/*
+ *
+ *  ____            _        _   __  __ _                  __  __ ____
+ * |  _ \ ___   ___| | _____| |_|  \/  (_)_ __   ___      |  \/  |  _ \
+ * | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
+ * |  __/ (_) | (__|   <  __/ |_| |  | | | | | |  __/_____| |  | |  __/
+ * |_|   \___/ \___|_|\_\___|\__|_|  |_|_|_| |_|\___|     |_|  |_|_|
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * @author PocketMine Team
+ * @link http://www.pocketmine.net/
+ *
+ *
+*/
+
+declare(strict_types=1);
+
+namespace pocketmine\block;
+
+use pocketmine\block\utils\CoralType;
+use pocketmine\item\Item;
+
+abstract class BaseCoral extends Transparent{
+
+	protected CoralType $coralType;
+	protected bool $dead = false;
+
+	public function __construct(BlockIdentifier $idInfo, string $name, BlockBreakInfo $breakInfo, CoralType $coralType){
+		parent::__construct($idInfo, $name, $breakInfo);
+		$this->coralType = $coralType;
+	}
+
+	public function getCoralType() : CoralType{ return $this->coralType; }
+
+	public function isDead() : bool{ return $this->dead; }
+
+	/** @return $this */
+	public function setDead(bool $dead) : self{
+		$this->dead = $dead;
+		return $this;
+	}
+
+	public function onNearbyBlockChange() : void{
+		if(!$this->dead){
+			$world = $this->pos->getWorld();
+
+			$hasWater = false;
+			foreach($this->pos->sides() as $vector3){
+				if($world->getBlock($vector3) instanceof Water){
+					$hasWater = true;
+					break;
+				}
+			}
+
+			//TODO: check water inside the block itself (not supported on the API yet)
+			if(!$hasWater){
+				$world->setBlock($this->pos, $this->setDead(true));
+			}
+		}
+	}
+
+	public function getDropsForCompatibleTool(Item $item) : array{
+		return [];
+	}
+
+	public function isAffectedBySilkTouch() : bool{
+		return true;
+	}
+
+	public function isSolid() : bool{ return false; }
+
+	protected function recalculateCollisionBoxes() : array{ return []; }
+}