Make section collapsable in the course index

As a user
I want to be able to collapse and expand sections
so I can focus on the section I'm working on

Users will be able to toggle sections to expand/collapse. The way to toggling will be an icon besides section title.

Collapsing and expanding sections won't affect section status in the course main content.

Prototype: No specific prototype for collapsing section, so linked to general prototype https://www.figma.com/file/OfCvqK069Oz6Fvqq2xcZWI/Create-a-course?node-id=6%3A0
 

Check the video attached for the desired effect of expand-collapse – as described in the screenshot above

• click on chevron : expand or collapse only
• click on title: goto + expand or collapse
• (optional) hover on the element : tooltip with expand or collapse

Acceptance criteria:

1. When the section is collapsed, no activity will be shown.
2. When the section is expanded, all activities except those with no title into the section will be shown.
3. The title of a section is a link to the section in the main content. Clicking/tapping in the section title doesn’t expand/collapse the section.
4. Beside the section title there is an icon to expand/collapse the section.
5. Expanding and collapsing actions are available both via mouse and keyboard.
6. By default all sections are collapsed except section 0.