Bug 5087: (QA follow-up) Rename the attribute to fit later API usage

Bug 5087: (QA follow-up) Rename the attribute to fit later API usage

This patch renames the introduced attribute for later usage on the API,
and changes the logic to use it the other way around.

It also adds a KEY for the flag, as it will be used in WHERE statements.

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
(cherry picked from commit 478093072000d01b2b5c20f05044e4bd3bbfeecd)

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>