feat(category): update list filter category

internal/validator/category_validator.go

@@ -118,5 +118,9 @@ func (v *CategoryValidatorImpl) ValidateListCategoriesRequest(req *contract.List
 		}
 	}
 
+	if req.Type != "" && req.Type != "parent" && req.Type != "child" {
+		return errors.New("type must be either 'parent' or 'child'"), constants.MalformedFieldErrorCode
+	}
+
 	return nil, ""
 }