Bug 35290: Sanitize field input on cataloguing/ysearch.pl

Bug 35290: Sanitize field input on cataloguing/ysearch.pl

This change sanitizies the field input on cataloguing/ysearch.pl

Test plan:
0. Apply the patch and restart/reload Koha
1a. "Add marc21_field_260b.pl plugin to 260$b in the Default framework"
1b. Go to http://localhost:8081/cgi-bin/koha/admin/marc_subfields_structure.pl?
op=add_form&tagfield=260&frameworkcode=#subbfield
1c. Choose "marc21_field_260b.pl" from the dropdown next to "Plugin"
1d. Click "Save changes"
2a. "Add new record"
2b. Go to http://localhost:8081/cgi-bin/koha/cataloguing/addbiblio.pl?frameworkcode=
3. Click on tab "2" and scroll down to 260 "b"
4. Type in "Ori" into 260 subfield b
5. Some autocomplete suggestions should appear

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>