RATIONALE
Channel model is a mail.thread enabled model behaving strangely with followers,
notifications and discuss. Its code should however be simplified to be more
self contained and avoid unwanted side effects on other models.
PURPOSE
Remove channel ability to follow records as it mainly adds noise without a lot
of added value. Simplify channel notification flow by using directly members
and not a delegation through a channel self-following trick. Remove followers
being channels and posting with added listeners being channels.
SPECIFICATIONS
In this commit we remove support of ``channel_ids`` parameter when posting
a message. This means we do not support notifying channels as side-part
of notification mechanism on a document. Either we post on a channel and
its members are notified, either we post on a business documents and its
followers are notified. There is no possibility to add channels as being
notified when posting a message.
This is done as a followup of removing followers being channel-based and
prepares ground to make channel use model / res_id as all other documents
inheriting form mail.thread.
LINKS
Task ID-2070632 (main task)
Task ID-2419762 (followup task)
COM PR odoo/odoo#62859
ENT PR odoo/enterprise#15172
UPG PR odoo/upgrade#2005
Thibault Delavallée
df013e76bc