Support `node-pg-migrate` by parsing `-- Down Migration`

Currently the migrations create the database and immediately drop it, because `node-pg-migrate` syntax is as follows

```sql
-- 1746712582483_create_users_table.sql

-- Up Migration

CREATE TABLE users (id text);

-- Down Migration

DROP TABLE users;
```
I can work around this by taking a schema dump, but I'd rather not setup a script for that for my whole team.
