PURPOSE
Cleanup code and flow of customer rating: routes, rating_apply, rating and
message creation and update.
SPECIFICATIONS
Cleanup code about rating controllers and rating_apply. Notably correctly
link a message to a rating once a feedback is posted, whatever the flow.
Update ``rating_apply`` to use either a token, either an existing rating to
udpate it and post a message. Always link the message and the rating to
be sure DB data are coherent.
This requires an update in several demo data to correctly set tokens on
ratings and use it in calls to ``rating_apply`` done in xml files.
Extract default subtype computation of rating_apply in a sub-method to allow
setting this parameter without having to deal with ``rating_apply`` details.
CODE CLEANUP
Split behavior that is generic but actually used only in project about stage
update based on rating. Move it directly in project. As it is used only once
and as generic approach is hardcoded based on fields names better keep it
localized.
Task-2812665 (Rating: Cleanup rating flow code)
Part-of: odoo/odoo#80707
