Added total tax to Carts, Orders, and Line Items

The commercetools Platform now exposes the total tax amount on a Cart, Order, LineItem, CustomLineItem, and ShippingInfo. Before, your application had to calculate that amount if you wanted to display it to your customers.

Changes:

• [API] Added optional totalTax field to TaxedPrice and TaxedItemPrice.
• [GraphQL API] Changed the TaxedPrice type:
  • Added the totalTax field to the TaxedPrice type.
  • Added the totalTax field to the TaxedItemPrice type.

The following changes were introduced in terms of GraphQL SDL:

extend type TaxedPrice {
  totalTax: Money
}

extend type TaxedItemPrice {
  totalTax: Money
}