Bug 36598: Enable CSRF protection for Mojolicious apps

Bug 36598: Enable CSRF protection for Mojolicious apps

Test plan:
1. Run bin/opac daemon -l http://*:3001/
2. Go to http://localhost:3001/cgi-bin/koha/opac-user.pl
3. With browser devtools, locate csrf_token hidden input within the
   login form and remove it or modify it
4. Try to submit the form with correct credentials, it should fail
   ("Wrong CSRF token")
5. Reload the page, try to log in normally without modifying the DOM, it
   should succeed
6. Run bin/intranet daemon -l http://*:3002/
7. Go to http://localhost:3002/cgi-bin/koha/mainpage.pl
8. With browser devtools, locate csrf_token hidden input within the
   login form and remove it or modify it
9. Try to submit the form with correct credentials, it should fail
   ("Wrong CSRF token")
10. Reload the page, try to log in normally without modifying the DOM,
    it should succeed
11. Run prove t/db_dependent/mojo/csrf.t

Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>