Handle Multiple Models in deployment

[FlorianPydde]

When training multiple models, the ado pipelines should be able to deploy all trained models into other environments.

The change need to be applied to:

• Training and registering script: should be able to save and register multiple models

• Deployment scripts: multiple models should be deployed to the next stage (view open branch: https://github.com/microsoft/dstoolkit-mlops-base/blob/feature/62-many-model-deployment/operation/execution/deploy_model.py)

• Scoring scripts: should be able to link to register models

• Configuration file: should be able to contain a list for aml_model variable (see example AML_models: https://github.com/microsoft/dstoolkit-mlops-base/blob/feature/62-many-model-deployment/configuration/configuration-aml.variables.yml)

• pipeline files: should be able to accept lists as arguments