Bug 14321: [QA Follow-up] Additional QA requests

Bug 14321: [QA Follow-up] Additional QA requests

This patch makes following requested changes:

[1] Renamed categorycode to uploadcategorycode (with atomicupdate file)
[2] Confirmation before deleting an uploaded file
[3] Label for Public checkbox can be clicked
[4] Back button on result list (not in plugin mode)
[5] Correct additional variable interpolation from sql queries

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Tested the db revision, unit test.
Uploaded temporary and permanent file, incl. plugin mode.
Deleted an upload.
Ran stage-marc-import.pl.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>