Refactor test utilities and enhance ASGI settings

- Cleaned up and standardized assertions in ApiTestMixin for API response validation.
- Updated ASGI settings to use os.environ for setting the DJANGO_SETTINGS_MODULE.
- Removed unused imports and improved formatting in settings.py.
- Refactored URL patterns in urls.py for better readability and organization.
- Enhanced view functions in views.py for consistency and clarity.
- Added .flake8 configuration for linting and style enforcement.
- Introduced type stubs for django-environ to improve type checking with Pylance.

location/apps.py

@@ -1,7 +1,8 @@
 from django.apps import AppConfig
 import os
 
+
 class LocationConfig(AppConfig):
     path = os.path.dirname(os.path.abspath(__file__))
-    default_auto_field = 'django.db.models.BigAutoField'
-    name = 'location'
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "location"