Bug 14321: Add two columns to uploaded_files

Bug 14321: Add two columns to uploaded_files

This patch adds uploaded_files.public and permanent.
Public will be used later to mark uploaded files as available via OPAC.
Permanent will be used to make the distinction between temporary and
permanent storage.

The db rev sets both flags for all current records (uploaded via the
plugin from BZ 6874).

Test plan:
[1] If you tested this before, drop the column public first.
[1] Run the dbrev.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>