PURPOSE
Merge rendering tools used in mail and sms templates as well as partially
in mailings and move them directly in mail.render.mixin.
SPECIFICATIONS
Move tools related to language computation from mail.template model to the
mail.render.mixin. It allows to update both
* mail.template: simply update calls accordingly;
* sms.template: remove code doing what is now available through mail.render
.mixin inherit;
Lang field is moved to mail.render.mixin as it is used notably for the language
computation. It therefore adds the field on mailing.mailing model although
not used currently.
LINKS
Task ID 1963529
Community PR odoo/odoo#32397
Thibault Delavallée
2835e0ba38