1) in this commit, improved portal chatter for messaging. when the user sends a message, the new message is updated in history without reloading page. instead of submitting a form which reloads page to send message we added rpc call to send message. 2) rating on courses is implemented by extending portal chatter, applied changes in website_slides to do reviews without reloading page 3) refactoring: cleaned or removed code eg. removed form and some input fields as data is not submitted as form anymore, introduced some methods to avoid duplication of code task-2054662 Closes https://github.com/odoo/odoo/pull/47746 closes odoo/odoo#47746 Signed-off-by: Samuel Degueldre <sdegueldre@users.noreply.github.com> Co-authored-by: ktr-odoo <ktr@odoo.com> Co-authored-by: Siddarth Gajjar <sga@odoo.com>