Bug 27029: Add data-biblionumber attribute to OPAC detail page

This patch adds a data-biblionumber attribute to the
div#catalogue_detail_biblio elements on opac-detail.pl, so that
Javascript running on the page can easily fetch and use the
record's biblionumber.

Signed-off-by: Mark Hofstetter <mark@hofstetter.at>, <koha@trust-box.at>

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

koha-tmpl/opac-tmpl/bootstrap/en/modules/opac-detail.tt

@@ -56,7 +56,7 @@
     <div class="container-fluid">
         <div class="row">
             <div class="col-lg-9">
-                <div id="catalogue_detail_biblio" class="maincontent">
+                <div id="catalogue_detail_biblio" class="maincontent" data-biblionumber="[% biblio.biblionumber %]">
 
                     <div id="bookcover">
                         [% IF ( biblio.title ) %]