ipatests: Add integration tests for External IdP support
    
    Tests for [RFE]: Added integration tests for external IdP
    authentication with keycloak-17 as identity provider.
    
    Related : https://pagure.io/freeipa/issue/8805
    Related: https://pagure.io/freeipa/issue/8803
    Related: https://pagure.io/freeipa/issue/8804
    
    Signed-off-by: Anuja More <amore@redhat.com>
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
    Reviewed-By: Mohammad Rizwan Yusuf <myusuf@redhat.com>