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.

views/templates/admin/form/customhtmlblock_edit.html.twig

@@ -21,6 +21,7 @@
                 $('.customhtmlblock-type-faq').hide();
                 $('.customhtmlblock-type-banner').hide();
                 $('.customhtmlblock-type-alert').hide();
+                $('.customhtmlblock-type-usp').hide();
                 $('.customhtmlblock-type-' + type).show();
             }