feature(backend): init stats app to get stats about site activity

backend/base_app/settings/main.py

@@ -64,6 +64,7 @@ INSTALLED_APPS = [
     "backend_app",
     "base_app",
     "external_data",
+    "stats_app",
     "webpack_loader",
     "django_filters",
 ]

backend/stats_app/admin.py

+from django.contrib import admin
+from stats_app.models import DailyConnections
+
+
+admin.site.register(DailyConnections)

backend/stats_app/apps.py

+from django.apps import AppConfig
+
+
+class StatsAppConfig(AppConfig):
+    name = "stats_app"