refactor tests and add new

src/argenta/command/flag/models.py

@@ -53,10 +53,7 @@ class Flag:
         if isinstance(self.possible_values, Pattern):
             return bool(self.possible_values.match(input_flag_value))
 
-        if isinstance(self.possible_values, list):
-            return input_flag_value in self.possible_values
-            
-        return False
+        return input_flag_value in self.possible_values
 
     @property
     def string_entity(self) -> str:
@@ -88,9 +85,9 @@ class InputFlag:
         self,
         name: str,
         *,
-        prefix: PREFIX_TYPE = "--",
         input_value: str,
-        status: ValidationStatus | None,
+        prefix: PREFIX_TYPE = "--",
+        status: ValidationStatus | None = None,
     ):
         """
         Public. The entity of the flag of the entered command