Issue #3611969: Configure the example registration form Cancel booking escape outcome

Follow-up to orchestra #3611961. The example yoyaku_booking registration form (n_form, webform collect) routes cancelled to the release step but no longer declared that outcome, so under the new webform escape-outcomes mechanism it would show no Cancel button. Configures outcomes: cancelled with label Cancel booking on n_form's webform interaction settings (mirroring n_payment).