GONRG-2017: Add manifest_ingestion test file to repo

Type of change

• Bug Fix
• Feature

Does this introduce a change in the core logic?

• [Yes]

Does this introduce a change in the cloud provider implementation, if so which cloud?

• AWS
• Azure
• GCP
• IBM

Updates description?

Add manifest_ingestion DAG to test Workflow service. The DAG does nothing but return Ok status to Workflow service.