feat(go): Port full Ananta private server to Go architecture

pkg/protocol/packet.go

@@ -0,0 +1,22 @@
+package protocol
+
+type RpcPacketKind byte
+
+const (
+	PacketKindUnknown RpcPacketKind = 0x00
+	PacketKindInvoke  RpcPacketKind = 0x01
+	PacketKindReturn  RpcPacketKind = 0x02
+	PacketKindNotify  RpcPacketKind = 0x03
+)
+
+type RpcPacket struct {
+	Kind     RpcPacketKind
+	MethodID uint32
+	InvokeID int32
+	Error    int32
+	Body     []byte
+}
+
+func (p RpcPacket) IsInvoke() bool { return p.Kind == PacketKindInvoke }
+func (p RpcPacket) IsNotify() bool { return p.Kind == PacketKindNotify }
+func (p RpcPacket) IsReturn() bool { return p.Kind == PacketKindReturn }