[FIX] im_livechat : fix send feedback from livechatter.
[FIX] im_livechat : fix send feedback from livechatter.

This commit fixes the send feedback by creating explicitely the
rating.
Before, we gave to the mail channel the rating values.
But as rating uses res_id and res_model, creating the rating
directly with correct values in res_id and res_model makes the magic.
The rating is correctly linked to the mail channel.

Task ID: 2076190
PR #37340
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo