Add expand/collapse button on new Unit Page MFE

[jmakowski1123]

Implement expand/collapse functionality on the new Unit MFE.

In order to avoid long load times, when a user opens a Unit page, all of the components will be auto-collapsed.

There will be two options to expand components.

1. Via an expand all/collapse all button
2. Via an expand/collapse button on each component.

Screenshots of the UI are below.

Tests for the feature are here: https://openedx.atlassian.net/wiki/spaces/OEPM/pages/4195909635/Tests+for+new+Unit+Page+MFE#Expand%2FCollapse-Button

[github-actions]

Thanks for your submission, @openedx/open-edx-project-managers will review shortly.

[jmakowski1123]

Will not pursue