AIP-84 Migrate the public endpoint Get DAG to FastAPI #42652

Description

Currently the Get DAG public endpoint is at api_connexion/endpoints/dag_endpoint.py under get_dag. It provides basic information of a DAG. We need to migrate it to the api_fastapi/views/public/dags.py under a get_dag or similar.

Features and functionality of the endpoint will remain unchanged.

Use case/motivation

AIP-84 cWiki Link: https://cwiki.apache.org/confluence/display/AIRFLOW/AIP-84+UI+REST+API

Related issues

Related to: #42370

Are you willing to submit a PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct