[IMP] sale: ask confirmation for SO cancellation

Before this commit, when cancelling a SO, the wizard opened only when
there were draft invoices or delivered picking in the order.

In order to complete the notification flow of the SO and avoid
unexpected  cancellation of orders, the user must now confirm
cancellation and gets to possibility to send an email notification.

task-2660895

Part-of: odoo/odoo#81569