Bug 33761: Alter query to remove items with active transfers from available list

Bug 33761: Alter query to remove items with active transfers from available list

Current code removes all items without an active transfer, and any with completed transfers.

This patch moves the conditionals for transfers into the join, then adds a new
condition to remove items with active transfers.

To test:
1 - Apply unit test patch only
2 - prove -v t/db_dependent/HoldsQueue.t
3 - It fails
4 - Apply second patch
5 - prove -v t/db_dependent/HoldsQueue.t
6 - Success!

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>