Add macro to refresh messages from htmx swap

eboutic/templates/eboutic/eboutic_billing_info.jinja

@@ -1,3 +1,5 @@
+{% from 'core/macros.jinja' import update_notifications %}
+
 <div id=billing-infos-fragment>
   <div
     class="collapse"
@@ -29,7 +31,6 @@
       >
     </form>
   </div>
-
   <br>
-  {% include "core/base/notifications.jinja" %}
+  {{ update_notifications(messages) }}
 </div>

eboutic/templates/eboutic/eboutic_checkout.jinja

@@ -1,7 +1,7 @@
 {% extends "core/base.jinja" %}
 
 {% block notifications %}
-  {# Notifications are moved inside the billing info fragment #}
+  {# Notifications are moved under the billing form #}
 {% endblock %}
 
 {% block title %}
@@ -60,6 +60,7 @@
       <div @htmx:after-request="fill">
         {{ billing_infos_form }}
       </div>
+      {% include "core/base/notifications.jinja" %}
       <form
         method="post"
         action="{{ settings.SITH_EBOUTIC_ET_URL }}"