Plutopulp/chat app integration

[plutopulp]

Pull request outline

Add chat functionality to container play page. In order for this to work, an extras field needs to be added to the pipeline.yaml config file with key-value model_type=chat, e.g.

runtime:
  container_commands:
    - apt-get update
    - apt-get install -y git
  python:
    version: "3.10"
    requirements:
      - pipeline-ai
accelerators: []
accelerator_memory: null
pipeline_graph: new_pipeline:my_new_pipeline
pipeline_name: chat-pipeline
extras:
  model_type: "chat"

Note that the extras are loaded from this yaml file on the container and returned as part of the response /v4/container/pipeline.