Currently the Send & Print wizard is stored as regular model and not a TransientModel. This cause multiple problems including concurrency ones. This PR switches the wizard back to a regular transient one. We instead store the values of the wizard that needs to be processed asynchronously in the related move. closes odoo/odoo#139311 Task-id: 3415101 Related: odoo/enterprise#49310 Signed-off-by: Laurent Smet (las) <las@odoo.com>