fix: modal save button + missing translations

- Replace form="id" cross-element approach with requestSubmit() for
  reliable save button wiring in modal footer
- Re-call _bindDirty after validation-error re-render so dirty guard
  is preserved across save attempts
- Translate missing Dutch strings: Order saved, Error saving order,
  Question details, View

templates/backoffice/question_bank/_form_body.html.twig

@@ -32,6 +32,6 @@
 {% if isModal ?? false %}
 <template data-modal-footer>
     <button type="button" class="btn btn-secondary" data-bs-dismiss="modal">{{ 'Cancel'|trans }}</button>
-    <button type="submit" form="{{ form.vars.id }}" class="btn btn-primary">{{ 'Save'|trans }}</button>
+    <button type="submit" class="btn btn-primary">{{ 'Save'|trans }}</button>
 </template>
 {% endif %}