Ticket 49281 - improve db2* tests
    
    Bug Description:  In lib389 50 we change how db2bak and db2ldif
    work, so we need to update our tests accordingly
    
    Fix Description:  Add start/stop as needed, and prevent
    the raw call to perl tools.
    
    https://pagure.io/389-ds-base/issue/49281
    
    Author: wibrown
    
    Review by: mreynolds (Thanks!)