CORE: Add database schema control, likely via an ORM

[cwang]

Is your feature request related to a problem? Please describe.

Right now, there's no db schema change control; all the tables are created on the fly. This is not fit for purpose as production-ready software.

Describe the solution you'd like See https://github.com/ozcanyarimdunya/python-orm for 3 mainstream ORMs as candidates. The safe choice is SQLAlchemy for sure

Describe alternatives you've considered See above for 3 ORM tools.

Additional context Ideally pick one having good integration with FastAPI.

[janaka]

Urgency lowered

Note: given database schema creation and initialisation has been added this isn't needed as much any more.