Bug 38118: Display columns if not empty in drawCallback

Bug 38118: Display columns if not empty in drawCallback

Instead of updating only when DT init is complete we are going to update
the visibility when the table will be redrawn.

Test plan:
1 - Find/Add a bib record with no items
2 - Add 20 items from Centerville
    Edit ->Edit items -> enter CENTER1 into barcode ->'Add multiple copies' -> 20
3 - Add 20 items from Fairview as above but enter 'FAIR1' for barcode and 'FAIR ITEM' as callnumber
4 - Add 1 item from Midway with barcode MIDWAY1
5 - Edit a midway patron to grant 'catalogue' and 'edit_items' permission - NOT edit_any_item
6 - Sign in as the patron above
7 - Find the record
8 - Note there is callnumber and actions/edit columns
9 - Go to page 2 of items - callnumber visible
10 - Go to page 3 - edit column

Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>