Move '_create_mailing_list' as a base mass mailing tool to make it easily
usable by most mail-related test addons.
Improve '_filter_mail' tool by allowing to give an additional 'email_from'
used to filter emails produced under a mock. When having similar records
mailed several times (e.g. several mailings triggered at the same time which
may happen for marketing automation tests) it eases finding the right email
linked to a given mailing / recipient.
Improve some logs to ease debugging, notably for marketing automation.
Task-3506681 (MA: Test cleanup)
Prepares Task-2981581 (MA: Fix trace duplication and various issues)
X-original-commit: aad84dda189e13d76a87e349a7d56d84e584879c
Part-of: odoo/odoo#143088