- Update database models to the new declarative mapping syntax
See https://docs.sqlalchemy.org/en/20/orm/mapping_styles.html#orm-declarative-mapping
- Make use of Flask-SQLAlchemy to manage database connections
- Remove cli command interface in favor of just deleting the
sqlite file and reseeding when no tables are detected.
- Add list of iso639_1 language codes and names, and add to seed list
- Other changes to file structure.
Oystein Kristoffer Tveit