Create deployment with extra config file

We have the way to create devenv with extra options passed as csv and json. However, for running a different flavour of airflow for prolonged period of tim, it will take additional communication to keep the extra options up-to-date. I propose storing those in airflow-common, as in https://gerrit.wikimedia.org/r/c/operations/deployment-charts/+/1318719.

Test plan:

atsuko@deploy1003:~/src/data-engineering/airflow-devenv$ python3 -m airflow_devenv \
    create -d test_k8s --branch T433388 \
    --extra-values values-airflow3.yaml \
    -f dags/kubernetes_pod_operator_dag.py

Airflow development environment provisioning parameters:
- instance name: dev-atsuko
- pulled git branch: T433388
- airflow-dags folder: test_k8s
- DAGs files to serialise: ['dags/kubernetes_pod_operator_dag.py']
- Extra values file: /srv/deployment-charts/helmfile.d/dse-k8s-services/_airflow_common_/values-airflow3.yaml

Bug: T433388 Closes T433388