fix(ingestion/airflow-plugin): fix AthenaOperator extraction

[steffengr]

The GenericSqlExtractor which is currently by the DataHub Airflow plugin to extract lineage information does not properly support the AthenaOperator and crashes with "AttributeError: 'AthenaOperator' object has no attribute 'sql'". This patch introduces a AthenaOperatorExtractor following the BigQueryInsertJobOperatorExtractor example to fix support for the AthenaOperator.

Fixes #11160

Checklist

• [x] The PR conforms to DataHub's Contributing Guideline (particularly Commit Message Format)
• [x] Links to related issues (if applicable)
• [ ] Tests for the changes have been added/updated (if applicable)
• [ ] Docs related to the changes have been added/updated (if applicable). If a new feature has been added a Usage Guide has been added for the same.
• [ ] For any breaking change/potential downtime/deprecation/big changes an entry has been made in Updating DataHub

[steffengr]

@hsheth2 Thank for looking at this! I don't see related tests in this module. Could you point me at an example? I don't have much experience with this code base.

[hsheth2]

@steffengr we have an integration test (https://github.com/datahub-project/datahub/blob/master/metadata-ingestion-modules/airflow-plugin/tests/integration/test_plugin.py) that runs a number of DAGs (e.g. https://github.com/datahub-project/datahub/blob/master/metadata-ingestion-modules/airflow-plugin/tests/integration/dags/snowflake_operator.py)

That'd probably be the easiest way to do it. Otherwise, we could also do a more targeted unit test in https://github.com/datahub-project/datahub/blob/master/metadata-ingestion-modules/airflow-plugin/tests/unit/test_airflow.py