Make nvmsgbroker_pipeline modular for the future use in the pipeline

[lyuzinmaxim]

For the future use in the final pipeline, it would be nice to refactor the current probe function (in nvmsgbroker_pipeline.py), and to split the logic.

Here are the proposals for splitting:

• logic for tensor operations (link) can be wrapped in a separate function
• logic for creating the message (link)

DoD:

• a modular probe function is working in the same way as before