Bug 21599: Fix item type creation by defining default values

Bug 21599: Fix item type creation by defining default values

Same as what we have in Koha::Patron->new, empty strings should not be
inserted in integer or date column type

DBD::mysql::st execute failed: Incorrect decimal value: '' for column 'defaultreplacecost' at row 1 [for Statement "INSERT INTO `itemtypes` ( `checkinmsg`, `checkinmsgtype`, `defaultreplacecost`, `description`, `hideinopac`, `imageurl`, `itemtype`, `notforloan`, `processfee`, `rentalcharge`, `searchcategory`, `sip_media_type`, `summary`) VALUES ( ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ? )" with ParamValues: 0="", 1="message", 2="", 3="xx", 4=0, 5='', 6="XX", 7=0, 8="", 9="", 10="", 11=undef, 12=""] at /usr/share/perl5/DBIx/Class/Storage/DBI.pm line 1832.

Test plan:
Create a new itemtype

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>