Add active nav state to work items

Annabel Dunstone Grayrequested to merge
work-items-nav into master

What does this MR do and why?

Adds active nav state to work items

Screenshots or screen recordings

Before After
Screenshot_2025-06-09_at_2.42.35_PM Screenshot_2025-06-09_at_2.39.48_PM

How to set up and validate locally

Look at work items (objectives, tasks etc http://gdk.test:3000/gitlab-org/gitlab-test/-/work_items/73)

Links

Merge request reports