Allow Blocks to specify their max stack size

src/block/Block.php

@@ -439,6 +439,13 @@ class Block{
 		return 0;
 	}
 
+	/**
+	 * Returns the maximum number of this block that can fit into a single item stack.
+	 */
+	public function getMaxStackSize() : int{
+		return 64;
+	}
+
 	/**
 	 * Returns the chance that the block will catch fire from nearby fire sources. Higher values lead to faster catching
 	 * fire.