Eliminate the use of `extract()` in `wp_list_comments()`. All unit tests pass.

See #22400.


git-svn-id: https://develop.svn.wordpress.org/trunk@28428 602fd350-edb4-49c9-b593-d223f7449a82
Eliminate the use of `extract()` in `get_post_reply_link()`.

See #22400.


git-svn-id: https://develop.svn.wordpress.org/trunk@28429 602fd350-edb4-49c9-b593-d223f7449a82