Bug 18980: Add remark next to "Anyone seeing this list" permission

Bug 18980: Add remark next to "Anyone seeing this list" permission

This is a follow-up of report 18228 that simplifies the permissions for
lists. It reapplies the idea behind bug 10865 by adding a remark next to
the Anyone permission if it is not actually effective. A next patch will
make it behave dynamically.

Note: The Anyone permission is not relevant if it is a private list that
has no shares. Note that looking at the prefs OpacAllowPublicListCreation
and/or OpacAllowSharingPrivateLists is not decisive. You should look at
list permissions and shares in the database; turning off the Sharing pref
does not automatically remove all shares in the system. It only blocks
creating new shares.

We only need changes in opac-shelves.tt and virtualshelves/shelves.tt.

Test plan:
[1] Verify that you see the remark now in OPAC and staff.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>