webui:tests: Add tests for realmd domains
    
    This patch expands WebUI testing on realmd domains
    page. The added tests are:
      test_add_single_labeled_domain
      test_dnszone_del_hooked_to_realmdomains_mod
      test_dns_reversezone_add_hooked_to_realmdomains_mod
      test_dnszone_add_hooked_to_realmdomains_mod
      test_del_domain_of_ipa_server_bug1035286
      test_add_non_dns_configured_domain_positive
      test_add_non_dns_configured_domain_negative
      test_del_domain_with_force_update
      test_del_domain_and_update
      test_del_domain_and_refresh
      test_del_domain_revert
      test_del_domain_undo_all
      test_del_domain_undo
      test_add_domain_and_update
      test_add_domain_with_trailing_space
      test_add_domain_with_leading_space
      test_add_empty_domain
      test_add_duplicate_domaini
      test_add_domain_and_revert
      test_add_domain_and_refresh
      test_add_domain_and_undo_all
      test_add_domain_and_undo
      test_add_domain_with_special_char
    
    Reviewed-By: Felipe Volpone <felipevolpone@gmail.com>
    Reviewed-By: Varun Mylaraiah <mvarun@redhat.com>