Shipping tax is missing

Problem/Motivation

In the Checkout payment gateway, the support for collecting and presenting shipping rates was added. Currently shipping rates do not advertise and include the tax rate however Vipps MobilePay Checkout API has the support for that.

Steps to reproduce

Proposed resolution

Add tax rate into https://git.drupalcode.org/project/vipps_mobilepay_commerce/-/blob/61b4b... and use that value when adding shipping adjustment in https://git.drupalcode.org/project/vipps_mobilepay_commerce/-/blob/61b4b...

Remaining tasks

User interface changes

API changes

Data model changes