Change how progress and completion is shown on Get Started/Learn GitLab

Summary

The progress tracking shown within our onboarding (Get Started/Learn GitLab) is currently shared across the namespace. This creates confusing UX when a user may be tracking what they have/have not yet completed.

While there is a long term effort planned to make the onboarding centric to the user instead of the namespace (epic), we believe that some iterative improvements in the short term will be a viable MVC solution to reduce user confusion and be better for short term planned experiments such as https://gitlab.com/groups/gitlab-org/-/epics/18707+

Solution:

Remove the following elements from Get Started (shown to trials)/Learn GitLab (shown to free users)

• The progress percentage in the navigation
• The progress bar on the tutorial
• Changing the to-do/done state behaviour
  • Even after the tutorial item has been completed, still allow for the task to be completed again

Rough design: