Add extra interfaces to make it easier to get at the actual blockstate serializer/deserializer

this still is a pain the ass, but it's much less so than before.

src/data/bedrock/block/CachingBlockStateDeserializer.php

@@ -23,7 +23,7 @@ declare(strict_types=1);
 
 namespace pocketmine\data\bedrock\block;
 
-final class CachingBlockStateDeserializer implements BlockStateDeserializer{
+final class CachingBlockStateDeserializer implements DelegatingBlockStateDeserializer{
 
 	/**
 	 * @var int[]

src/data/bedrock/block/CachingBlockStateSerializer.php

@@ -23,7 +23,7 @@ declare(strict_types=1);
 
 namespace pocketmine\data\bedrock\block;
 
-final class CachingBlockStateSerializer implements BlockStateSerializer{
+final class CachingBlockStateSerializer implements DelegatingBlockStateSerializer{
 
 	/**
 	 * @var BlockStateData[]

src/data/bedrock/block/DelegatingBlockStateDeserializer.php

@@ -0,0 +1,29 @@
+<?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\data\bedrock\block;
+
+interface DelegatingBlockStateDeserializer extends BlockStateDeserializer{
+
+	public function getRealDeserializer() : BlockStateDeserializer;
+}

src/data/bedrock/block/DelegatingBlockStateSerializer.php

@@ -0,0 +1,29 @@
+<?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\data\bedrock\block;
+
+interface DelegatingBlockStateSerializer extends BlockStateSerializer{
+
+	public function getRealSerializer() : BlockStateSerializer;
+}