Add scheduled automation task and update URL routing

- Introduced a new scheduled task for executing automation rules every 5 minutes in the Celery beat schedule.
- Updated URL routing to include a new endpoint for automation-related functionalities.
- Refactored imports in various modules to align with the new business layer structure, ensuring backward compatibility for billing models, exceptions, and services.

backend/igny8_core/modules/automation/urls.py

@@ -0,0 +1,15 @@
+"""
+URL patterns for automation module.
+"""
+from django.urls import path, include
+from rest_framework.routers import DefaultRouter
+from .views import AutomationRuleViewSet, ScheduledTaskViewSet
+
+router = DefaultRouter()
+router.register(r'rules', AutomationRuleViewSet, basename='automation-rule')
+router.register(r'scheduled-tasks', ScheduledTaskViewSet, basename='scheduled-task')
+
+urlpatterns = [
+    path('', include(router.urls)),
+]
+