feat : 서버 실패 코드 메시지 기능 추가

MMOTestServer/MMOserver/Packet/PacketBody.cs

@@ -516,6 +516,31 @@ public class DamagePacket
     }
 }
 
+// ============================================================
+// 에러
+// ============================================================
+
+public enum ErrorCode : int
+{
+    // 파티 (10021~)
+    PARTY_ALREADY_IN_PARTY = 10021,
+    PARTY_JOIN_FAILED      = 10022,
+    PARTY_NOT_IN_PARTY     = 10023,
+    PARTY_DELETE_FAILED    = 10024,
+}
+
+// ERROR (서버 -> 클라)
+[ProtoContract]
+public class ErrorPacket
+{
+    [ProtoMember(1)]
+    public ErrorCode Code
+    {
+        get;
+        set;
+    }
+}
+
 // ============================================================
 // 파티
 // ============================================================