Bug 34910: Do not allow checkout for anonymous patron

Bug 34910: Do not allow checkout for anonymous patron

The anonymous patron circulation page should show an alert message and not allow check-out.

1) Configure an existing borrowernumber in system preference
   AnonymousPatron
2) Go to circulation page of this borrower :
   /cgi-bin/koha/circ/circulation.pl?borrowernumber=x
3) Check you see alert 'This is the anonymous patron, so circulation is disabled.'

Signed-off-by: Kelly McElligott <kelly@bywatersolutions.com>
Signed-off-by: Johanna Miettunen <johanna.miettunen@haaga-helia.fi>
Signed-off-by: Päivi Knuutinen <paivi.knuutinen@joensuu.fi>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>