Bug 14686: Add allows_add_by to check permissions for uploading

Bug 14686: Add allows_add_by to check permissions for uploading

The three permissions in tools/upload-file.pl are moved to a custom
routine in DBIx's UploadedFile.pm. An additional granular permission
upload_general_files is added. (The dbrev patch will contain it too.)
At some point in time this could be moved to a Koha::Object class.

The routine is tested in Upload.t.

Test plan:
[1] Run t/db_dependent/Upload.t
[2] If you only apply this patch, you can also test uploading with a
    user that has edit_catalogue but does not have tools or circulate.
    Upload status should say: Denied.

Signed-off-by: Mirko Tietgen <mirko@abunchofthings.net>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Brendan Gallagher <bredan@bywatersolutions.com>