[Parsers] Add support of libraries not copied to Airflow DAG repository
It is possible that some of the parsers that will be integrated with OSDU will be commercial solutions and owners of these parsers will not donate their code to OSDU. Parser developers should follow an established standard and project structure and do parser development in their own reporsitory. Ingestion team should document this process and project structure. The same should be done for Airflow DAGs.