add internal getInputBuffer() (#2472)

common/src/main/java/com/viaversion/viaversion/protocol/packet/PacketWrapperImpl.java

@@ -427,6 +427,10 @@ public class PacketWrapperImpl implements PacketWrapper {
         this.id = id;
     }
     
+    public ByteBuf getInputBuffer() {
+        return inputBuffer;
+    }
+
     @Override
     public String toString() {
         return "PacketWrapper{" +