Bug 14440: get_template_and_user can not have an empty template_name (quote*_ajax.pl)

 Bug 14440: get_template_and_user can not have an empty template_name (quote*_ajax.pl)

This patch uses check_api_auth instead of get_template_and_user.

Test plan:
Confirm that you are still able to access to the quote editor with the
edit_quotes permission.
Confirm that you are not if you don't have the permission.

wget your_url/cgi-bin/koha/tools/quotes/quotes_ajax.pl
should return "403 : Forbidden."

Signed-off-by: Indranil Das Gupta (L2C2 Technologies) <indradg@gmail.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>