Rework database layer, get rid of flask-migrate

compendium_v2/__init__.py

compendium_v2/alembic.ini

compendium_v2/db/__init__.py

compendium_v2/db/model.py

compendium_v2/db/models.py

compendium_v2/db/survey.py

compendium_v2/migrations/__init__.py

compendium_v2/migrations/alembic.ini

compendium_v2/migrations/env.py

compendium_v2/migrations/migration_utils.py

...s/20221128_1223_1e8ba780b977_initial_data_entry_models.py

compendium_v2/migrations/versions/95577456fcfd_initial_db.py