[Migration] Migrate data towards PSQL

[shashankmc]

Problem

1. Current setup is distributed and loads main extracted rechtspraak data in DynamoDB.
2. With growing features, internal discussion has led the team to conclude to move everything towards Postgres.

Solution

• Script to move schema from DynamoDB to Postgres.
• Migration script to move existing data and its associated metadata to Postgres.
• Data validation
• Update ETL pipelines to load to Postgres.
• Update documentation
• Test and validate with front end application
• Merge branch to main
• Update server hosting Airflow