Fix word wrapping in the "Edit Review" dialog.

I recently replaced the multiple CodeMirror boxes with inlineEditors in the
"Edit Review" dialog. One small bit of fallout from this is that the word
wrapping wasn't correct when saving a long comment. The problem here was that
the 'pre' element inside the review dialog didn't have our `.pre-wrap` macro.

Testing done:
Set a long body top field and saw that it wrapped correctly.

Reviewed at https://reviews.reviewboard.org/r/6371/