Allow/handle input of script input arguments

[robert-clegg-tessella]

User job scripts may take input arguments to run, which need to be specified in the body to the piezo web app and passed onto the spark operator

Acceptance criteria

• Submit job handler accepts the argument: arguments
• arguments is optional and if not provided then is not included in the manifest
• arguments is formatted as an array
• Each value in arguments is supplied in the spark job manifest in the same order as provided in arguments