Test if server installer lock Bind9 recursion
    
    This test is to check if recursion can be configured.
    It checks if newly added file /etc/named/ipa-ext.conf
    exists and /etc/named.conf should not have
    'allow-recursion { any; };'. It also checks if ipa-backup
    command backup the /etc/named/ipa-ext.conf file as well
    
    related : https://pagure.io/freeipa/issue/8079
    
    Signed-off-by: Mohammad Rizwan Yusuf <myusuf@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>