Item Separator in inputBinding should be arbitrary string

[Deleted user]

We should be able to use an arbitrary string as an item separator. This is to enable the use case where we have the command line being like -I a.txt -I b.txt -I c.txt with the raw CWL being like

  - id: input
    type: 'File[]?'
    inputBinding:
      position: 0
      prefix: '-I'
      itemSeparator: ' -I '