Refactor icon rendering; update render_icon macro to accept extra_class parameter and adjust button icons in combobox for better state management

templates/settings.html

@@ -72,10 +72,3 @@
     </div>
 </form>
 {% endblock %}
-
-{% block script %}
-    const icons = {
-        add: `{{ icons.render_icon('plus', 16)|safe }}`,
-        edit: `{{ icons.render_icon('pencil', 16)|safe }}`,
-    };
-{% endblock %}