Bug 21750: Move collection code to its own column on checkins table

Bug 21750: Move collection code to its own column on checkins table

To test:
 1 - Set 'ShowAllCheckins' to show
 2 - Set a collcection code for an item
 3 - Check it in
 4 - Note it displays in the the 'Item type' column
 5 - Apply patch
 6 - Check it in again
 7 - Note the new 'Collection' column
 8 - Hide/show the column using column visibility on the checkins page
 9 - Go to Admin->Configure columns
10 - Test the various settings for this column and check in the item to
make sure they work as expected

Signed-off-by: Devinim <kohadevinim@devinim.com.tr>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>

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