Provide an interactive shell that allows using Airflow Connections

### Description Many projects provide an interactive shell with all necessary bootstrapping done. For example Django's `django-admin shell` command. It would be nice to have this on Airflow too. A command like `airflow shell` could be used. It would make sense if the same kind of code that it used inside of tasks could be used interactively (e.g. not some parallel sdk API). For example if you have a PythonOperator that calls a function like: ``` def pg_do_stuff(conn_id): pg_hook = PostgresHook(postgres_conn_id=conn_id) with pg_hook.get_sqlalchemy_engine().begin() as conn: # do stuff ... ``` In our `airflow shell` command, you could similarly do: ``` > from airflow.providers.postgres.hooks.postgres import PostgresHook > pg_hook = PostgresHook(postgres_conn_id="my_conn_id") > conn = pg_hook.get_sqlalchemy_engine().connect() > conn.execute(...) ``` ### Use case/motivation There are various use cases, here are two: #### Production debugging Given: * you have access to a shell on your productive Airflow instance. * you have some connections (DB, HTTP, whatever) that are used in existing Airflow DAGs, that, due to firewall restrictions, you can not access from your workstation. * a previously working DAG stops delivering the data you expect it to. Perhaps there's an error, or perhaps the data received simply doesn't look like it is supposed to. Then: It would be nice to be able to connect to a python shell on the prod (or integration) Airflow instance and interactively run commands, use the defined connections, and investigate what is happening. #### Local development Given: * you are developing a task to pull and process data from a data source * you are not familiar with the data delivered Then: It would be nice to have an interactive python shell that allows you to use that connection interactively. ### Related issues Discussion: https://github.com/apache/airflow/discussions/60334 ### Are you willing to submit a PR? - [ ] Yes I am willing to submit a PR! …