test: improve and expand translation and localization tests

- Add comprehensive translation coverage and error aggregation to test_locale_messages.py
- Add LocaleMiddleware to test configuration
- Add new tests for token validation and localization

Author: mahdirahimi1999

tests/conftest.py

@@ -2,6 +2,7 @@ def pytest_configure():
     from django.conf import settings
 
     MIDDLEWARE = (
+        'django.middleware.locale.LocaleMiddleware',
         "django.middleware.common.CommonMiddleware",
         "django.contrib.sessions.middleware.SessionMiddleware",
         "django.contrib.auth.middleware.AuthenticationMiddleware",