Bug 33876: Add class for styling

Bug 33876: Add class for styling

To test:
1. Checkout and item that has a public and nonpublic note.
2. In the checkout table ( Title column ) notice the notes display. If you use the browser dev tools to inspect you'll notice a "-" outside of any HTML element.
3. Apply patch.
4. See the '-' is now inside of a html element with class of seperator.

Signed-off-by: Sam Lau <samalau@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 6091a938c1c148cbeab6ff27f5261c6fe64d1463)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>