Bug 11139: Add support for multiple values in AdvancedSearchTypes

Bug 11139: Add support for multiple values in AdvancedSearchTypes

AdvancedSearchTypes syspref can be multivalued, opac-topissues.pl
have to support that.

AdvancedSearchTypes can have one or more of the following values:
'itemtypes', 'ccode', 'loc'.  But this patch adds support only for
itemtypes and ccode.  AdvancedSearchTypes can still contain 'loc' but it
will change nothing to the behaviour of opac-topissues.pl.

This patch also removes duplicate code in template (the "Refine your
search" form was written in two different places)
This introduces a small behaviour change: when there is no results,
instead of having the form in the center of the page, it remains in the
left sidebar and we have a "No results" message in the main area.

Depends on bug 14788

Tested on top of 14788. Works as expected.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>