The conversion of background images for mass_mailing doesn't support the conversion of shapes on them (limitation of html2canvas), and emails should not contain videos. This removes these options for mass_mailing. Since the video option was added in place by `website`, this adds an option in its template so it can be disabled. A similar option was added for shapes, which depends on images being enabled as well. task-2856858 closes odoo/odoo#91314 Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>