Bug 26557: (bug 23463 follow-up) Fix Batch import when incoming records contain itemn...

Bug 26557: (bug 23463 follow-up) Fix Batch import when incoming records contain itemnumber

Prior to ug 23463 AddItemFromMarc where calling AddItem, that did not
take into account the itemnumber field.
Now that we are using Koha::Item, we need to remove the items.itemnumber
field from the MARC record

Test plan:
1 - find an existing bib in your system with just one item
2 - export that bib with the item attached
3 - delete the barcode from your item in Koha
4 - stage your exported marc file for reimport, match on biblionumber, set it to Always Add Items
5 - confirm that the bib matches and the incoming 952 is parsed
6 - click "Import this batch into the catalog"

=> Without this patch you get (in the logs, or hidden)
manage-marc-import.pl: DBD::mysql::st execute failed: Duplicate entry '23' for key 'PRIMARY' [for Statement "INSERT INTO `items` ( `barcode`, `biblioitemnumber`, `biblionumber`, `ccode`, `cn_sort`, `cn_source`, `damaged_on`, `dateaccessioned`, `datelastborrowed`, `datelastseen`, `holdingbranch`, `homebranch`, `itemcallnumber`, `itemlost_on`, `itemnumber`, `itype`, `location`, `more_subfields_xml`, `onloan`, `permanent_location`, `replacementpricedate`, `timestamp`, `withdrawn_on`) VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, current_timestamp, ? )" with ParamValues: 0="BC_23", 1=8, 2=8, 3="REF", 4='CN__23', 5=undef, 6=undef, 7="2014-09-04", 8=undef, 9="2014-09-04", 10="FPL", 11="FPL", 12="CN_23", 13=undef, 14="23", 15="BK", 16="GEN", 17=undef, 18=undef, 19="GEN", 20="2014-09-04", 21=undef] at /usr/share/perl5/DBIx/Class/Storage/DBI.pm line 1836.
manage-marc-import.pl: DBIx::Class::Storage::DBI::_dbh_execute(): Duplicate entry '23' for key 'PRIMARY' at /kohadevbox/koha/Koha/Object.pm line 169
manage-marc-import.pl: {UNKNOWN}: Transaction aborted: Duplicate ID. Rollback failed: DBIx::Class::Storage::txn_rollback(): Refusing to roll back without a started transaction at /kohadevbox/koha/tools/manage-marc-import.pl line 253 at /kohadevbox/koha/tools/manage-marc-import.pl line 253

=> With this patch applied, the new item must be added to the existing bibliographic record

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>