Allow users to subscribe to being notified when a new participation is
completed on a survey.
As surveys expecting hundreds of participants will not be followed in
such a way, we will only post these messages if there are any followers
on the survey.
We add a check on any subscriber belonging to group_survey_user
to further limit creating messages of which no one can make use.
A test of this feature is included.
Adding a `_sudo` for good measure while we're here, it does
not change anything.
Minor docstring change in `mail.followers` _get_recipient_data`.
Task-3389133
closesodoo/odoo#128922
Signed-off-by: Thibault Delavallee (tde) <tde@openerp.com>
Florian Charlier
707cb82117