Bug 19975: Fix search by tags at the OPAC

Bug 19975: Fix search by tags at the OPAC

This bug has certainly be caused by
  commit 091d6c513bcbee224ff06477e79be48cea7fe825
    Bug 17843: Replace C4::Koha::getitemtypeinfo with Koha::ItemTypes

The reason is quite simple, in Koha::ItemType->translated_description
(called in opac-search.pl l.229) there is an eval to know if we have
access to the translated description of the item type, to avoid
retrieving it again.

The evaluation of $@ later in opac-search.pl is supposed to test the 2
eval made few lines before (a "normal" search, without tags), but
$@ contains the error message from the *last* eval command.
So we are raising an error that have been correctly handled in
Koha::ItemType.

Test plan:
At the OPAC, click Tag cloud, then click any of the tags

=> Without the patch you get
Koha::ItemType::get_column generated this error: DBIx::Class::Row::get_column(): No such column 'translated_description' on Koha::Schema::Result::Itemtype at /usr/share/koha/lib/Koha/Object.pm line 307

=> With the patch applied the page is correctly displayed

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>