Resolve "User dropdown in filtered search does not load avatar on `master`"

What does this MR do?

It fixes the url problem for the avatar templates in the search box.

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

String Replacement.

Does this MR meet the acceptance criteria?

• Tests
  • Added for this feature/bug
  • All builds are passing
• Review
  • Has been reviewed by UX
  • Has been reviewed by Frontend
• Conform by the merge request performance guides
• Conform by the style guides
• Branch has no merge conflicts with master (if it does - rebase it please)
• Squashed related commits together

What are the relevant issue numbers?

Closes #35729 (closed)