Represents the portions that sum up to the totalGross field of a TaxedPrice.
The portions are calculated from the [TaxRates](ctp:api:type:TaxRate).
If a Tax Rate has [SubRates](ctp:api:type:SubRate), they are used and can be identified by name.
Tax portions from Line Items with the same `rate` and `name` will be accumulated to the same tax portion.
Represents the portions that sum up to the
totalGross
field of a TaxedPrice.