Bug 33643: Add page-section to 'scan index' page in staff interface

This adds the white background. As we do on other pages I have
chosen to include the h2 heading within the page-section.

To test:
* Go to advanced search in staff interface
* Activate 'More options'
* Check checkbox for scan indexes
* Switch to author (especially when using Elasticsearch)
* Search for C
* On the result list verify there is no white background/page section
* Apply patch
* Repeat test - background should be present now

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: Nicolas Giraud <nicolas.giraud@inlibro.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

koha-tmpl/intranet-tmpl/prog/en/modules/catalogue/results.tt

@@ -369,6 +369,7 @@
                 <!-- Search Results Table -->
                 [% IF ( total ) %]
                     [% IF ( scan ) %]
+                    <div class="page-section">
                         <h2>Scan index</h2>
                         <form action="/cgi-bin/koha/catalogue/search.pl" method="get">
                            <label for="scan-index">Scan index:</label>
@@ -425,6 +426,7 @@
                                 [% END %]
                             </table>
                         </form>
+                    </div>
                     [% ELSE # /IF scan %]
 
                         <div id="searchresults">