Change the ProductPriceModel.PriceWithDiscount property to PriceWithoutDiscount property

[skoshelev]

The Price property itself already assumes that it reflects the lowest possible price, that is, already with all discounts, so there is no need for a separate PriceWithDiscount property. It is better to create PriceWithoutDiscount to store the price without a discount.

Also, do not forget to change the use of these properties on the views accordingly.

[KaranChadha10]

I've created a PR (#7656) to address this issue. Please review when possible. Thanks!