better mode code

src/tmtccmd/tc/service_200_mode.py

@@ -1,16 +1,23 @@
 """
 @brief      Core components for mode commanding (custom PUS service)
 """
+import enum
 import struct
 
 
-def pack_mode_data(object_id: bytearray, mode_: int, submode_: int) -> bytearray:
-    """
-    Mode 0: Off, Mode 1: Mode On, Mode 2: Mode Normal, Mode 3: Mode Raw
+class Modes(enum.IntEnum):
+    OFF = 0,
+    ON = 1,
+    NORMAL = 2,
+    RAW = 3
+
+
+def pack_mode_data(object_id: bytearray, mode: Modes, submode: int) -> bytearray:
+    """Mode 0: Off, Mode 1: Mode On, Mode 2: Mode Normal, Mode 3: Mode Raw
     """
     # Normal mode
-    mode = struct.pack(">I", mode_)
+    mode_packed = struct.pack("!I", mode)
     # Submode default
-    submode = struct.pack('B', submode_)
-    mode_data = object_id + mode + submode
+    submode_byte = struct.pack('B', submode)
+    mode_data = object_id + mode_packed + submode_byte
     return mode_data