The "Your comment is awaiting moderation." message relied upon the comment author cookie being set. However, since it's now possible to opt-out of that cookie, submitting a comment won't show the comment preview when the comment is placed in moderation.
To avoid this issue, we now include a hash in the redirect URL, allowing the site to identify that a preview of the moderated comment should be displayed.
Props imath, tomdxw, birgire, lakenh, azaozz, pento.
Fixes#43857.
git-svn-id: https://develop.svn.wordpress.org/trunk@44659 602fd350-edb4-49c9-b593-d223f7449a82
9dfde992ee