PURPOSE
In livechat, rating emojis(happy, neutral and sad) display with percentage of
how happy visitors are with the particular channel, click on that will show all
ratings of livechat channels and stat button is visible while creation, if it
has no rating.
SPECIFICATION
Add one computed field "rating_count" for the model 'rating.parent.mixin' which
shows the total rating amount of a particular channel and based on that field
invisible the stat button when the count is 0.
Also, display only happy face emoji with the percentage of happiness on
the kanban view of livechat channel, click on that will only display ratings of
the particular channel.
Task- 2471714
closesodoo/odoo#67336
Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>