Updated the layout for the display of the 'Add to Cart' button.

Added an environment for the cart button «hotengine-shop-product-cart-parent», which may contain additional classes «hotengine-shop-product-compare-exists» and «hotengine-shop-product-favorite-exists» if product comparison or the 'Add to Favorites' icon is enabled, with a position «AFTER» or «BEFORE» the cart button. Furthermore, if the quantity toggle for adding products to the cart is enabled, the element will include the additional class «hotengine-shop-product-spinner-block».
Updated the icons for switching the product list display style.
Updated the style for displaying products in list view