Extend JobSubmitHandler to accept jar files

The job submission through the CLI first uploads all require jars to the blob server, sets the blob keys in the jobgraph, and then uploads this graph to The JobSubmitHandler which submits it to the Dispatcher.

This process has the downside that it requires jars to be uploaded to the blobserver before submitting the job graph, which does not happen via REST.

I propose an extension to the the JobSubmitHandler to also accept an optional list of jar files, that were previously uploaded through the JarUploadHandler. If present, the handler would upload these jars to the blobserver and set the blob keys.