Stabilization, ease integration, new file status tracking storage, slimmed down dependencies

[huanchh2]

5.0.0

• Simplified Ray bootstrap, previously this was tied to FastAPI life cycle, and the only reason FASTAPI was introduced as a dep
• Removed domain specific data model fields and revert Ray Worker to more generic form
• Removed Python dependencies no longer needed
• replace Clickhouse with Postgres as permanent storage to track File proessing status
• Wired up Alembic to support Postgres migration supported
• make repo publishable as a python package to ease integration
• name spaced ENV variabled to be bound as configs
• additional Make targets to support development, schema migration.. etc