Fixes for inline documentation for hooks in wp-comments-post.php.

Adds missing `@since` versions, spacing, and language tweaks.

See #26869, #25229, [25249].

Built from https://develop.svn.wordpress.org/trunk@27144


git-svn-id: http://core.svn.wordpress.org/trunk@27011 1a063a9b-81f0-0310-95a4-ce76da25c4cd