Bug 28959: (follow-up) Adjust more places in which 'category' was used

Bug 28959: (follow-up) Adjust more places in which 'category' was used

Some links still had category.

I propose we use explicit public=1 and public=0 when links to public/private are side by side.
Otherwise whe just use /cgi-bin/koha/opac-shelves.pl?op=list using default value 0.

Signed-off-by: David Nind <david@davidnind.com>
JK: Adjust commit title
Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>