Course index should be opened by default first time a user access the course

This is what was decided together with UX team:

• On a large screen (desktop), the course index will be EXPANDED by default, so it will be expanded the first time the users access a course
• On large screens, the drawer state will be saved in the user preferences, so if the user collapses it, it should remain collapsed
• In small screens, the course index is always collapsed by default even if the user expands it and reloads the page, despite the user preference
• In small screens, the state of the drawer is not saved in the user preference