Bug 31289: Hide Article requests column in circulation rules when ArticleRequests...

Bug 31289: Hide Article requests column in circulation rules when ArticleRequests syspref is disabled

This patch hides the Article requests column in the large circulation
rules table when the ArticleRequests system preference is disabled.

To test:
0) Apply patch
1) With ArticleRequests disabled, go to Administration > Circulation and fines
   rules
2) Scroll right in the first table
--> There isn't any mention of article requests in the table
3) Scroll down to see the other tables in the page
--> There are no other article requests tables
4) Enable ArticleRequests in Administration > System preferences
5) Go back to the Circulation and fines rules and refresh the page
6) Scroll right in the first table
--> There should be an article requests yes/no column
7) Scroll down to see the other tables in the page
--> There are other article requests tables, Default open article requests
    limit and Default article request fees

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>