feat(standard-styling) Enhance search and styling

Improves search bar with SVG icon support for better visual consistency.

Adds utility SCSS file for managing global styles like heading selectors.

Introduces a checkmark SVG asset and reorganizes custom SCSS files following the 7-in-1 structure for better maintainability.

Comments out optional USP bar code in header.tpl to allow easy activation.

falcon/templates/_partials/header.tpl

@@ -37,7 +37,6 @@
         <div class="header-top js-header-top">
             <div class="header-top__content pb-md-0 py-2">
                 <div class="container">
-
                     <div class="row header-top__row">
 
                         <div class="col flex-grow-0 header-top__block header-top__block--menu-toggle d-block d-md-none">