Feature/panto agent docker

Describe the MR

• Create a docker for panto-agent and add it to the docker-compose files ;
• Add a panto-agent in the all-in-one docker image

Why was this MR needed?

To distribute the panto-agent to docker users.

Extra-care points?

Issue #460 (closed) raises a question on the configuration process. It needs to be addressed before the merge, either by a technical solution, or by an extra effort on documentation.

Does this MR meet the acceptance criteria?

• Documentation created/updated
• CHANGELOG updated
• Unit Tests added/updated

What are the relevant issue numbers?

closes #460 (closed)

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