Provide a sample boot application that provides a enhanced scheduling for SCDF

[cppwfs]

SCDF provides cron expression for scheduling the launching of tasks. However, users sometimes need more advanced scheduling for launching their tasks. In these cases they can use enterprise level schedulers or something like quartz to schedule these task launches using dataflow via its RESTful API.
Provide a sample Spring Boot application that utilzes Quartz to demonstrate this capability.

[injae-kim]

public void schedule() // SCDF schedule API
  launcher.getScheduler().schedule(scheduleRequest);
}

I think SCDF schedule API internally uses each platform(e.g. k8s)'s scheduler to schedule task.

they can use enterprise level schedulers or something like quartz to schedule these task launches using dataflow via its RESTful API.

Can you share simple example code to implement above way? (Replace launcher.getScheduler() to quartz?)

Thanks @cppwfs ! If you busy I think I can make PR too :)