AO3-6834 Add Parent Thread link to unreviewed comments

[minionluvr]

Pull Request Checklist

• Have you read "How to write the perfect pull request"?
• Have you read the contributing guidelines?
• Have you added tests for any changed functionality?
• Have you added the Jira issue number
  as the first thing in your pull request title (e.g. AO3-1234 Fix thing)
• Do you have fewer than 5 pull requests already open? If not, please wait
  until they are reviewed and merged before creating new pull requests.

Issue

https://otwarchive.atlassian.net/browse/AO3-6834

Purpose

Made changes so that when an unreviewed comment is a reply, a Parent Thread link is available. This gives the reviewer context for approval.
The changes in this PR only add the link to the Parent Thread, not the parent comment (the 'commentable'/specific comment being replied to), so there can still be some confusion in the case where the unreviewed comment is a deeply nested reply in some thread.

Testing Instructions

Refer to Jira Issue. I added a scenario for testing.

Credit

minionluvr (she/her)

[brianjaustin]

Hi, minionluvr!

Thank you for working on this! The changes look good to me with 1 comment, once that's resolved I can approve the PR. In the meantime, I've updated the Jira issue status to In Review, so no one will mistakenly create a duplicate pull request.

If you'd like the ability to comment on, assign, and transition issues in the future, you're welcome to create a Jira account! You can just reply here with the account name and we'll set up the permissions for you. (It makes things a bit easier for us on the organizational side if the Full Name on your Jira account either closely matches the name you'd like us to credit in the release notes or includes it in parentheses, e.g. "Nickname (CREDIT NAME).")

Thanks again for contributing! If you have any questions, you can contact us at [email protected].

[brianjaustin]

Could you add a trailing line here? For a few reasons (https://stackoverflow.com/a/5813359 and a few of the other answers there), it's better to have it than not. If you use VS Code, that can do it for you automatically: https://stackoverflow.com/a/44704969

[brianjaustin]

Thanks!