Bug 33568: Fix local cover images

Bug 33568: Fix local cover images

We need to reprocess the images when the table is refreshed, to do that
we teach verify_cover_images to go through a given container instead of
the whole document, and pass a call back function to build_items_table
that will be called when DataTables will have redrawn the table
(drawCallback).

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Laurence Rault <laurence.rault@biblibre.com>
Signed-off-by: Emily Lamancusa <emily.lamancusa@montgomerycountymd.gov>
Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>