feat(main): Introduce USP block type and custom classes for HTML groups

This release adds a new "USP" (Unique Selling Proposition) block type,
allowing for flexible display of image-based selling points with optional links.

Additionally, administrators can now assign custom CSS classes to Custom HTML Groups,
enhancing layout and styling capabilities.

Includes a refinement to the FAQ accordion template to ensure questions without answers
do not display a collapse button, improving usability.

Updates module version to 1.13.0 with a database upgrade script for the new `custom_class` column.

upgrade/upgrade-1.13.0.php

@@ -0,0 +1,21 @@
+<?php
+
+if (!defined('_PS_VERSION_')) {
+    exit;
+}
+
+function upgrade_module_1_13_0($module)
+{
+    $existing = Db::getInstance()->executeS(
+        'SHOW COLUMNS FROM `' . _DB_PREFIX_ . 'ws_customhtml_group` LIKE \'custom_class\''
+    );
+
+    if (!empty($existing)) {
+        return true;
+    }
+
+    return Db::getInstance()->execute(
+        'ALTER TABLE `' . _DB_PREFIX_ . 'ws_customhtml_group`
+         ADD COLUMN `custom_class` VARCHAR(128) NOT NULL DEFAULT \'\' AFTER `title`'
+    );
+}