11ec42a ipatests: refactor FileBackup helper

Authored and Committed by sorlov 6 months ago
    ipatests: refactor FileBackup helper
    
    * `cp` now preserves all attributes of original file, there is no reason
      to select only some of them
    * backup is now restored with `mv` instead of `cp` to avoid leaving junk
    
    Related to: https://pagure.io/freeipa/issue/8115
    
    Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>