feat: a better database migration and seeding process

[Armando Magalhães]

Is your feature request related to a problem? Please describe.
The current database migration and seeding are fairly trivial:

• in development it leverages the default behaviour of the postgres docker image, to run all scripts provided in a folder when initializing an empty database.
• in production, there is none (which is the problem)

Implementing a better database migration process would help to apply changes to the database schema in production safely.

[Armando Magalhães]

dbmate was introduced and this can be closed