Restructure "net" packages

src/main/java/net/encryption/PacketCodec.java

@@ -0,0 +1,9 @@
+package net.encryption;
+
+import io.netty.channel.CombinedChannelDuplexHandler;
+
+public class PacketCodec extends CombinedChannelDuplexHandler<PacketDecoder, PacketEncoder> {
+    public PacketCodec(ClientCyphers clientCyphers) {
+        super(new PacketDecoder(clientCyphers.getReceiveCypher()), new PacketEncoder(clientCyphers.getSendCypher()));
+    }
+}