feat: batch processing

Author: ikalachy

src/main/java/io/neonbee/internal/codec/RawBatchResultMessageCodec.java

@@ -24,7 +24,7 @@ public RawBatchResultMessageCodec() {
     @Override
     public void encodeToWire(Buffer buffer, RawBatchResult result) {
         Buffer payload = result.buffer();
-        if (result.hasBuffer() && payload != null) {
+        if (result.hasBuffer()) {
             buffer.appendInt(payload.length());
             buffer.appendBuffer(payload);
         } else {