Bug 35141: Catch ES search exceptions in link_bibs_to_authorities, warn, and continue

Bug 35141: Catch ES search exceptions in link_bibs_to_authorities, warn, and continue

This patch simplay adds an eval and a warning to link_bibs_to_authorities to catch any errors while searching and continue linking.

To test:
1 - edit /etc/kohia/sites/kohadev/koha-conf.xml and add to elasticsearch stanza
    <request_timeout>0</request_timeout>
2 - perl misc/link_bibs_to_authorities.pl
3 - It dies immediately
4 - Apply patch
5 - perl misc/link_bibs_to_authorities.pl
6 - Now it tries every record, throwing warnings along the way, but completes

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>