Bug 33457: (QA follow-up) Use js-patron-format instead

Bug 33457: (QA follow-up) Use js-patron-format instead

This patch updates the code to use the $patron_to_html js function
rather than replicating it locally.. this means if in the future we
introduce further fixes/improvements to the display they're affect here
too.

Test plan
1) As for the original implementation, confirm the fix is still fixed

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit 4732d1080900b2437b1d30642e4ec6644ad6c900)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>