[FEATURE]: Allow for creating extensions using db:push

### Describe what you want

I'm using drizzle-kit to do my pg migrations but need to add the `vector` extension. To do this I need to run `CREATE EXTENSION IF NOT EXISTS vector` before creating my table with `vector` column types.

I can't see a way to run this CREATE EXTENSION migration before the db:push command is run using my schema.ts file. Is this possible or does it require a new feature for drizzle-kit?