feat: add missing getSize method to CustomBlockData

Author: TheBjoRedCraft

surf-api-bukkit/surf-api-bukkit-server/src/main/kotlin/dev/slne/surf/surfapi/bukkit/server/impl/pdc/block/CustomBlockData.kt

@@ -129,6 +129,10 @@ class CustomBlockData(val block: Block) : CustomBlockPersistentDataContainer {
         return pdc.serializeToBytes()
     }
 
+    override fun getSize(): Int {
+        return pdc.size
+    }
+
     companion object {
         fun getKey(block: Block): NamespacedKey {
             return key("x${block.x and 15}y${block.y}z${block.z and 15}")