For legacy reasons, the course renderings uses a format setting to know
if the page is multiple sections per page or a single section per page.
This format specific dependency is not solved using a get_course_display
format method any plugin can extend.
Now content and course index sections have special mutations to store
the collapsed preferences. This way the backend implementation is
independent of the frontend one and can use caches or other kind of
optimizations of necessary.
Move the section visible logic to the format base class. This way format
plugins can decide whenever a section is visible or not instead of using
format custom settings from core.
The course index is the first UI component that implements the new
drawers and the reactive components. The course index uses the course
state to present the current course structure and changes whenever
that structure change.
Andrew Nicols