Adds support for a new Backstage integration with the Apache Airflow workflow
management platform. This implementation has been tested with Apache Airflow v2
API authenticating with basic auth through the Backstage proxy plugin.
Supported functionality include:
- Information card of version information for the Airflow instance
- Information card of instance status (health) for metadatabase and scheduler
- Table of DAGs with meta information and status, along with a link to view
details in the Airflow UI
Signed-off-by: Colton Padden <colton.padden@fastmail.com>