Bug 18354 Adding item type attribute to cover image div

Bug 18354 Adding item type attribute to cover image div

This adds item type so we can do things with javascript.

To Test:

1.) Do a search on OPAC
2.) Inspect element to confirm item type is not present
3.) Apply patch
4.) Do a search on OPAC to confirm item type is present as a class

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>