What does this MR do?
Addresses "Auto-expand a discussion note when we arrive via anchor" (issue #19304 (closed))
Are there points in the code the reviewer needs to double check?
Let me know if the code is consistent with community standards (not 100% sure about indentation of chained jQuery actions)
I don't think this MR warrants any unit tests or documentation, but let me know if you disagree. I'll add the requisite CHANGELOG entry upon approval.
Why was this MR needed?
Currently, if a discussion is accessed via a permalink to an "outdated" diff discussion, the anchor will not bring you to the expected part of the page.