fix(i18n): normalize manage language-switch next URL

mandelstudio/templates/oxyan/headers/partials/carbasa-user-bar.html

@@ -3,7 +3,7 @@
 <div class="header-right">
     <form action="{% url 'set_language' %}" method="post" class="ms-lang-switcher me-2" aria-label="Language switcher">
         {% csrf_token %}
-        <input name="next" type="hidden" value="{{ request.get_full_path }}">
+        <input name="next" type="hidden" value="{{ language_neutral_url_path|default:request.path|untranslated_url }}">
         <label for="header-language-switcher" class="visually-hidden">{% trans "Language" %}</label>
         <select id="header-language-switcher" name="language" class="form-select form-select-sm" onchange="this.form.submit()">
             <option value="nl" {% if LANGUAGE_CODE == 'nl' %}selected{% endif %}>NL</option>