Add test cases for FHIR

[csafreen]

1. FHIR ingestion endpoint
2. FHIR data load plugin
3. ETL Template - FHIR to OMOP
4. ETL Template - QuestionnaireResponse 5q-5d-5l
   https://drive.google.com/drive/folders/1jazDSSUSCQETB0kC-E3ZRdhD4FpbrRzF