Add Change the job class API in zosJobs package

[frankgiordano]

See https://www.ibm.com/docs/en/zos/2.4.0?topic=interface-change-job-class

    Parameters
    ----------
    jobname: str
        The name of the job
    jobid: str
        The job id on JES
    class_name: str
        The name of class to be set to
    modify_version: str
        Default ("2.0") specifies that the request is to be processed synchronously.
        For asynchronous processing - change the value to "1.0"

    Raises
    ------
    ValueError
        Thrown if the modify_version is invalid

    Returns
    -------
    StatusResponse
        A JSON object containing the result of the request execution