test: add non-reg test checking pkinit after server install
    
    Add a test with the following scenario:
    ipa-server-install (with ca and pkinit enabled)
    check that pkinit is properly enabled:
    ipa-pkinit-manage status must return "enabled"
    the KDC cert must be signed by IPA CA
    
    Related to: https://pagure.io/freeipa/issue/7795
    
    Reviewed-By: François Cami <fcami@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>