Bug 8280: Add koha set and item fields to pqf.properties

Bug 8280: Add koha set and item fields to pqf.properties

This patch adds a 'koha' set to the pqf properties and maps some basic
koha fields to all for searchign

To test:
1 - Apply patch
2 - cp etc/z3950/pqf.properties /etc/koha/sites/kohadev/z3950/pqf.properties
3 - sudo koha-z3950-responder --restart kohadev
4 - Test a search:
    curl -XGET "http://localhost:2100/biblios?version=1.1&operation=searchRetrieve&query=koha.itemtype=BK&maximumRecords=60&recordSchema=marcxml"
5 - Test other fields added:
    koha.withdrawn
    koha.lost
    koha.classification-source
    koha.materials-specified
    koha.damaged
    koha.restricted
    koha.cn-sort
    koha.notforloan
    koha.ccode
    koha.itemnumber
    koha.homebranch
    koha.holdingbranch
    koha.location
    koha.barcode
    koha.onloan
    koha.itemtype

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
[EDIT] Copied the changes from z3950 to zebradb too.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>