Fix note highlight being added when you don't have a URL fragment hash #note_xxx

What does this MR do?

• Fix note highlight being added when you don't have a URL fragment hash #note_xxx

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

• Should we massage to boolean a different way? https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12293#note_32956032

Why was this MR needed?

• In https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/12098, we introduced adding a .target to help with the lost highlight on edits. When there isn't a fragment hash in the URL(#note_xxx), the boolean expression used to toggle the class can evaluate to null which jQuery doesn't assume as a force parameter and just toggles instead of assuming as false.

Does this MR meet the acceptance criteria?

• Tests
  • Added for this feature/bug
  • All builds are passing
• 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 #33916 (closed)