4a1cb7e ipatests: rewrite test for requests routing to subordinate suffixes

Authored and Committed by sorlov 3 years ago
    ipatests: rewrite test for requests routing to subordinate suffixes
    
    The original test had some issues:
    * it was doing many actions not related to the tested issue which obscured
      actual test scenario
    * subordinate suffix was hard coded in the test which prevented the test
      from checking original issue in case AD domain name did not match this
      hard coded value
    * Invocation of commands on AD controller was failing in some environments
    
    Other improvements:
    * added docstring with test details
    * added guard assertions for test preliminary conditions
    
    Related to https://pagure.io/freeipa/issue/8554
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>