input: Write a python function to extract all item names from a Django QuerySet and return them as a list.
  assert extract_item_names(Item.objects.all()) == ['Item1', 'Item2', 'Item3']
  assert extract_item_names(Item.objects.filter(price__gt=50)) == ['ExpensiveItem1', 'ExpensiveItem2']
  assert extract_item_names(Item.objects.none()) == []
output: def extract_item_names(queryset):
      return [item.name for item in queryset]