Nuke Block->meta, split into variant and state properties, lots of cleanup

This is a major change to the way block metadata is handled within the PM core. This separates variant metadata (which really ought to be part of the ID) from state metadata, and in a couple of cases flattens separate states of blocks together.

The result of this is that invalid variants can be much more easily detected, and additionally state handling is much cleaner since meta is only needed at the serialize layer instead of throughout the code.

src/pocketmine/block/Wood.php

@@ -23,46 +23,29 @@ declare(strict_types=1);
 
 namespace pocketmine\block;
 
-use pocketmine\block\utils\PillarRotationHelper;
+use pocketmine\block\utils\PillarRotationTrait;
 use pocketmine\item\Item;
+use pocketmine\math\Facing;
 use pocketmine\math\Vector3;
 use pocketmine\Player;
 
 class Wood extends Solid{
+	use PillarRotationTrait;
+
 	public const OAK = 0;
 	public const SPRUCE = 1;
 	public const BIRCH = 2;
 	public const JUNGLE = 3;
 
-	protected $id = self::WOOD;
-
-	public function __construct(int $meta = 0){
-		$this->setDamage($meta);
-	}
-
 	public function getHardness() : float{
 		return 2;
 	}
 
-	public function getName() : string{
-		static $names = [
-			self::OAK => "Oak Wood",
-			self::SPRUCE => "Spruce Wood",
-			self::BIRCH => "Birch Wood",
-			self::JUNGLE => "Jungle Wood"
-		];
-		return $names[$this->getVariant()] ?? "Unknown";
-	}
-
 	public function place(Item $item, Block $blockReplace, Block $blockClicked, int $face, Vector3 $clickVector, Player $player = null) : bool{
-		$this->meta = PillarRotationHelper::getMetaFromFace($this->meta, $face);
+		$this->axis = Facing::axis($face);
 		return parent::place($item, $blockReplace, $blockClicked, $face, $clickVector, $player);
 	}
 
-	public function getVariantBitmask() : int{
-		return 0x03;
-	}
-
 	public function getToolType() : int{
 		return BlockToolType::TYPE_AXE;
 	}