ipa-restore: adapt for 389-ds switch to LMDB
    
    ipa-restore is relying on the presence of specific directories,
    e.g. /var/lib/dirsrv/slapd-/db/ipaca, to detect
    which backends are in use (userRoot or ipaca).
    
    With the switch to LMDB, these directories do not exist and the
    restore fails finding the ipaca backend.
    
    Use lib389.cli_ctl.dblib.run_dbscan utility instead to
    check which backends are present.
    
    This method was been introduced in 389ds 2.1.0 and works with
    Berkeley DB and LMDB.
    
    Add a --data option to the ipa-backup and ipa-restore tasks to do
    only an LDIF backup and restore. Also add the ability to restore by
    backend.
    
    Add new tests to do a data-only backup and restore.
    
    Fixes: https://pagure.io/freeipa/issue/9526
    
    Signed-off-by: Rob Crittenden <rcritten@redhat.com>
    Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>