ADD Thread mode execution for jobs and subjobs.

[IonesioJunior]

Description

For development and debug purposes we want to run our helm job/subjobs in thread mode instead of multiprocessing mode.
This can be very useful in development scenarios where we want to debug things using pdb or similar tools.

Affected Dependencies

• Hagrid Orchestra.launch
• Node.named function
• ZMQQueueConfig parameters
• Queue APICallMessageHandler

How has this been tested?

• Notebook testing both threading / multiprocessing strategies and their outcomes (subjob results, logs,etc.).
• Provide instructions so we can reproduce.
  • Run nested_syft_function notebook
  • Just execute it as it is (default: thread_workers = False) to run jobs in multiprocessing mode.
  • ADD thread_workers=True to run jobs and subjobs in threading mode.