Add tier badge to sidebar

What does this MR do and why?

Add tier badge to sidebar

fixes: https://gitlab.com/gitlab-org/gitlab/-/issues/571795 EE: true

References

Screenshots or screen recordings

tier-badge

How to set up and validate locally

1. Setup gdk to simulate SaaS - https
2. Navigate to a group on a free plan
3. Verify the "Free" badge appears inside the sidebar next to "Group"
4. Hover over the badge to verify the popup displays in the correct location.
5. Navigate to a project on a free plan
6. Verify the "Free" badge appears inside the sidebar next to "Project"

MR acceptance checklist

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Related to #571795