AO3-5977 Hide "Approve All Unreviewed Comments" button from admins on works

[WelpThatWorked]

Issue

https://otwarchive.atlassian.net/browse/AO3-5977

Purpose

Hides the "Approve All Unreviewed Comments" button if an admin is viewing a work with comment moderation turned on.

Credit

Jake Faulkner

[sarken]

Hi, Jake, and thanks for the pull request!

I've left a review comment, and while there's already a test in features/admins/admin_post_news.feature that checks that the button is visible on news posts, we'd appreciate it if you could add a test to features/admins/admin_works.feature that ensures the button isn't visible on works.

I've assigned the Jira issue to you and set its status to In Review so no one will mistakenly create a duplicate pull request. I've also given your account permission to comment on, assign, and transition issues in the future.

Thanks again for contributing! If you have any questions, you can contact us at otw-coders@transformativeworks.org.

[WelpThatWorked]

Test added, threw in a check for the per-comment "Approve" button as well, since I don't see it anywhere else.

Used the helper, and decided to let it hide the button on works with no unreviewed comments as well, since the button would do nothing in that case.

[sarken]

Thank you!