Support injection of JobOperator

jakarta batch spec 2.1 requirement:

10.4. JobOperator

A JobOperator instance can be obtained in two ways:

  Via a factory pattern:
     JobOperator jobOper = BatchRuntime.getJobOperator();

Via a CDI Bean:

    @Inject JobOperator jobOper;  // E.g. field injection (any CDI injection mechanism can
     be used)