Add support for defining virtual SCSI controllers

[devblackops]

Add support for defining virtual SCSI controllers and associating virtual disks to them

Example:

disks = @(
    @{
        name = 'Hard disk 1'
        sizeGB = 50
        type = 'flat'
        format = 'Thick'
        volumeName = 'C'
        volumeLabel = 'NOS'
        SCSI = '0:0'
    }
    @{
        name = 'Hard disk 2'
        sizeGB = 100
        type = 'flat'
        format = 'Thick'
        volumeName = 'D'
        volumeLabel = 'Data'
        SCSI = '1:0'
    }
)