Applies new styling to the header, shopping cart, and search bar components.
Creates new scss files for header and swiper layouts.
Replaces x.svg.
These changes create a more consistent and modern user interface.
New method created in is_themecore module: Uses use PrestaShop\PrestaShop\Core\Util\ColorBrightnessCalculator and adds as smarty function in SmartyHelperFunctions.php
