This branch is just for "good to have" optional stand-alone sass features.
In this commit, I aimed to make some things more like bootstrap 5 for ease of use. I changed the grid breakpoints to match that of Bootstrap 5's and added media query mixins that are more logical like in bootstrap 5.
New method created in is_themecore module: Uses use PrestaShop\PrestaShop\Core\Util\ColorBrightnessCalculator and adds as smarty function in SmartyHelperFunctions.php