add iban validation

app/javascript/template_builder/field_settings.vue

@@ -745,6 +745,7 @@ export default {
         '^[^@\\s]+@[^@\\s]+\\.[^@\\s]+$': 'email',
         '^https?://.*': 'url',
         '^[0-9]{5}(?:-[0-9]{4})?$': 'zip',
+        '^[A-Z]{2}[0-9]{2}(?: ?[A-Z0-9]){11,30}$': 'iban',
         '^[0-9]+$': 'numbers_only',
         '^[a-zA-Z]+$': 'letters_only'
       }