Misc Python 3 fixes for ipaserver.secrets
    
    bytes/str fixes for LDAP data, JSON encoding and temp files.
    
    Require jwcrpyto 0.4.2 with fix for RHBZ #1476150
    
    https://pagure.io/freeipa/issue/4985
    
    Signed-off-by: Christian Heimes <cheimes@redhat.com>
    Reviewed-By: Simo Sorce <ssorce@redhat.com>
    Reviewed-By: Stanislav Laznicka <slaznick@redhat.com>