[ADD] website_sale_aplicoop: re-implement clear search button

Added × button to clear the search input field. When clicked:
- Clears the search text
- Updates lastSearchValue to prevent polling false-positive
- Calls infiniteScroll.resetWithFilters() to reload all products from server
- Maintains current category filter
- Returns focus to search input

The button appears when text is entered and hides when search is empty.

website_sale_aplicoop/views/website_templates.xml

@@ -473,15 +473,12 @@
             <div class="col-md-7">
               <!-- CRITICAL: This input is NOT inside a form to prevent Odoo from transforming it -->
               <!-- It must remain a pure HTML input element for realtime_search.js to detect value changes -->
-              <!-- TODO: Re-add clear button wrapper after fixing initialization issues
               <div style="position: relative;">
                 <input type="text" id="realtime-search-input" class="form-control realtime-search-box search-input-styled" placeholder="Search products..." autocomplete="off" style="padding-right: 40px;" />
                 <button type="button" id="clear-search-btn" class="btn btn-link" style="position: absolute; right: 5px; top: 50%; transform: translateY(-50%); padding: 0; width: 30px; height: 30px; display: none; color: #6c757d; text-decoration: none; font-size: 1.5rem; line-height: 1;" aria-label="Clear search" title="Clear search">
                   ×
                 </button>
               </div>
-              -->
-              <input type="text" id="realtime-search-input" class="form-control realtime-search-box search-input-styled" placeholder="Search products..." autocomplete="off" />
             </div>
             <div class="col-md-5">
               <select name="category" id="realtime-category-select" class="form-select">