Added the ability to update when importing the "quantity of goods in stock" by a mathematical expression.

Added the ability to update when importing the "quantity of goods in stock" not only by a numerical value, but also by a mathematical expression.

Added the ability to update when importing the "quantity of goods in stock" by a mathematical expression.

Added informing about unfinished purchase.Added option to separate address fields in the checkout form.Tabs with de ions in the product card have been replaced.