Allow to return <mail.mail> records and found outgoing emails when using
asserts. It eases doing checks in some specific tests e.g. checking
notification layout usage in emails. Indeed this is quite low level and
does not really deserves its own assert tooling methods.
Update tool method generating attachment data to ease name tweak when required
in tests.
Also update query counters, and fix a test not running locally.
Task-3046371 (Mail: Better Language Support in Composer)
X-original-commit: odoo/odoo@b32d937b37
Part-of: odoo/odoo#114511
Thibault Delavallée
3147d09b90