VWM shelf management commands for 7210 SAS-Mxp and 7210 SAS-T

config
    - system 
        - [no] vwm-shelf vwm-shelf-id [vwm-type vwm-type] [create]
            - card card-id
                - [no] card-type card-type
                - [no] shutdown
            - [no] shutdown