Switch to YAML for work order files

[Yadunund]

The work order descriptions are currently stored as JSON files. eg pick_and_place.json. This makes it easy to cat the contents when populating the ExecuteWorkOrder request from CLI. Once the request is sent to the system orchestrator, it ends up parsing the string into a YAML::Node.

To benefit from the various advantages of the YAML format, we could consider saving these descriptions as YAML files directly. For example, we can have pick_and_place.yaml

workInstructionName: Pick and Place
item:
  SkuId: productA
  description: productA
  unit: dummy_unit
  quantity: 1.0
  quantityPerPallet: 1.0
steps:
  - processId: place_on_conveyor
    name: Pick and Place
  - processId: pick_from_conveyor
    name: Pick and Place

And rely on CLI tool like yq to send the work order after parsing the yaml into a dict/json

ros2 action send_goal /system_orchestrator/execute_order nexus_orchestrator_msgs/action/ExecuteWorkOrder "{order: {work_order_id: '23', work_order: '$(yq -j "." config/pick_and_place.yaml)'}}"

If ros2 action gets support for --yaml-file similar to what was implemented for ros2 topic, we could directly call

ros2 action send_goal /system_orchestrator/execute_order nexus_orchestrator_msgs/action/ExecuteWorkOrder --yaml-file pick_and_place.yaml

But here the work_order_id field would also need to be included in the YAML file.