Bug 9043: Changes to the advanced search page

Bug 9043: Changes to the advanced search page

This patch adds 2 new sysprefs: OpacAdvSearchOptions and
OpacAdvSearchMoreOptions.

These sysprefs are multivalued and you can add or remove some elements on
the adv search page.

This patch allows to display/hide some entries in the advanced search
page at the OPAC.
On this way, it is possible to configure the search options to display.

Test plan:
1/
Fill OpacAdvSearchOptions with Item types and Languages.
Fill OpacAdvSearchMoreOptions with Item types, Languages and Location.
On the advanced search page, verify the Location is only displayed for
the "More options" view.
2/ Try different settings for these prefs
3/ Remove all entries for the OpacAdvSearchMoreOptions and verify that
the "More options" does not displayed additional options.
4/ Remove all entries for the OpacAdvSearchOptions and verify that the
"normal view" does not displayed any options.

Note that this patch only affects the bootstrap theme.

Signed-off-by: Koha Team Lyon 3 <koha@univ-lyon3.fr>
Signed-off-by: Jacek Ablewicz <abl@biblos.pk.edu.pl>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>