Bug 24857: Add ability to set item group when adding a new item

Bug 24857: Add ability to set item group when adding a new item

During cataloging a user may wish to add an item to a group when
creating a new item

This patch also copies the group description to the enumchron field

To test:
1 - Browse to details page for a record
2 - Create or ensure the record has item group(s)
3 - Click New->New item
4 - Note the bottom of the page has a form to attach to existing group, or create new
5 - Note when a group is selected the enumchron field is populated
6 - Confirm item is saved to group when saved

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>