refactor: adjust chunk sending (#2770)

- synchronise on the chunk GET object (when available)
 - kick it off to be run at some point on the main server thread

worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/adapter/BukkitGetBlocks.java

@@ -2,6 +2,6 @@ package com.fastasyncworldedit.bukkit.adapter;
 
 public interface BukkitGetBlocks {
 
-    void send(int mask, boolean lighting);
+    void send();
 
 }

worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/adapter/NMSAdapter.java

@@ -137,7 +137,7 @@ public class NMSAdapter implements FAWEPlatformAdapterImpl {
         if (!(chunk instanceof BukkitGetBlocks)) {
             throw new IllegalArgumentException("(IChunkGet) chunk not of type BukkitGetBlocks");
         }
-        ((BukkitGetBlocks) chunk).send(mask, lighting);
+        ((BukkitGetBlocks) chunk).send();
     }
 
 }