Make the 'created_at' field in shoppingcart products consistent with …

…the datetime format of Django and our project

backend/api/orders_views.py

@@ -167,6 +167,9 @@ def destroy(self, *args, **kwargs):
             )
         shopping_cart.remove(product_id)
         logger.info(MESSAGE_ON_DELETE)
+        # TODO: add details on fields types and responses after __iter__ method
+        # (as there are no serializer) to api docs (swagger) for shopping cart list
+        # and shopping cart post endpoints
         return Response(
             {
                 "products": shopping_cart.__iter__(),

backend/orders/shopping_carts.py

@@ -1,6 +1,5 @@
-from datetime import datetime, timezone
-
 from django.conf import settings
+from django.utils import timezone
 
 from products.models import Product
 
@@ -27,7 +26,7 @@ def add(self, product, quantity):
                 "category": p.category.slug,
                 "quantity": quantity,
                 "final_price": p.final_price,
-                "created_at": int(datetime.now(timezone.utc).timestamp()),
+                "created_at": timezone.localtime().isoformat(),
                 "amount": p.amount,
                 "measure_unit": p.measure_unit,
             }