Resolve "Overview of locked files displays HTML instead of relative time srting"

What does this MR do?

Fix display bug for lock file timestamp on index page

Are there points in the code the reviewer needs to double check?

Ensure that translation for time_ago_with_tooltip is covered by javascript library

Why was this MR needed?

Please see #5508 (closed)

Screenshots (if relevant)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• API support added
• Tests added for this feature/bug
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
  • Has been reviewed by Backend
  • Has been reviewed by Database
• Conform by the merge request performance guides
• Conform by the style guides
• Squashed related commits together
• Internationalization required/considered
• If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan
• End-to-end tests pass (package-qa manual pipeline job)

What are the relevant issue numbers?

Closes #5508 (closed)