[MERGE][IMP] website{_profile, _slide,_forum,*} : improve slides integration...

[MERGE][IMP] website{_profile, _slide,_forum,*} : improve slides integration in user profile and add karma generation

Purpose of the merge is to continue the work done from PR #30988.
This completes the website profile page,  gamifies the under development eLearning [1][2]
and continues integration between eLearning and the forum.

This merge contains notably:
- Complete profile page with course progression detail and eLearning certifications
- Apply Karma gains on various action on the eLearning
- Allow to set the communication type on eLearning course at creation (frontend)
- Redesign website users page

See sub commits for more details.

Merge linked to task ID 1922159 (elearning gamification / website_profile)
and task ID 1940516 (forum comments) PR #31097.

[1] see task ID 1902304 (main eLearning task) PR #29876.
[2] see task ID 1936153 (new homepage for slides) PR #30770.

closes odoo/odoo#31109