Bug 7703: (follow-up) Treat no items like none available

Bug 7703: (follow-up) Treat no items like none available

This patch modifies the holds template so that during the
multi-hold process, titles with no items attached are treated the same
way as titles with no items available (items exist but cannot be place
don hold):

 - The row showing such a record will say "No items are available to be
    placed on hold."
 - The pickup location dropdown will be hidden.

To test, follow the previous test plan and confirm that these change are
reflected. Now that the pickup location field isn't present for titles
without items you should be able to complete the holds process.

Signed-off-by: Sally <sally.healey@cheshiresharedservices.gov.uk>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>