Brings some love to this neglected screen:
* format `comment_content`, instead of escaping in one massive block of text
* only wrap the comment date in a link if the comment permalink exists
* include link to the Edit Comment screen at the bottom of the comment_content
* update the message styles to match other screens
* append `#wpbody-content` to the comment email message links for accessibility
Props johnbillion, rachelbaker, afercia, melchoyce, karmatosed.
Fixes#34133
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