Add db command for listing migrations with their status

Similar to `rails db:migrate:status`. But we'll have to figure out how to display/organize (combine?) any migrations in slices

I'm thinking it could be called `hanami db migrations` (versus the command to migrate the db which is `hanami db migrate`). Not specific to a name though, maybe `hanami db list_migrations` would be better, to keep the commands as verbs. The rest of our commands are all one word though.

We may want to implement this here then eventually move it over to `rom-sql`.