Add missing alarm volume 'normal' (#899)

Also logs a warning in feature repr if value not in choices and fixes the returned string to be consistent with valid values.

kasa/smart/modules/alarmmodule.py

@@ -64,7 +64,7 @@ class AlarmModule(SmartModule):
                 attribute_setter="set_alarm_volume",
                 category=Feature.Category.Config,
                 type=Feature.Type.Choice,
-                choices=["low", "high"],
+                choices=["low", "normal", "high"],
             )
         )
         self._add_feature(