Purpose
=======
This commit is enhancing the website_slides module.
Specifications
==============
It changes placeholders for certain fields, it changes helpers in some
of the views.
It updates some of the main views of the menus and corrects wordings
inside of them.
It activates the Graph and Pivot views for the reporting of
Courses, Reviews and Quizzes.
It cleans up some of the measures inside of the Pivot and Graph views
of each menus where it is available.
It also merges 2 models: slide.slide.link and slide.slide.resource into
slide.slide.resource with a type Selection field.
This is done in order to create a single table for the additional
resources of a Content.
It also improves the front-end of the module with minor changes.
It fixes the problem of long names inside of breadcrumbs.
It also adds a message when there is no leaderboard in /profile/users.
task-2597345
See odoo/enterprise#20480
See odoo/upgrade#2784
Part-of: odoo/odoo#75646
Thomas Josse
91db19c187