Bug 28769: Remove tabloop from cataloguing plugins

Bug 28769: Remove tabloop from cataloguing plugins

There is a "tabloop" variable that is passed from the add item form logic to the cataloguing plugins.
But there is confusion, sometimes it's an iterator ($i) and sometimes (batchMod.pl) an array.

Actually this tabloop variable is never used from cataloguing plugins, we should remove it.

Test plan:
Read the code and confirm the above.
You can also test a couple of plugins and confirm that they are still
working.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>