[FEATURE]: migrations in TypeScript / `drizzle-kit generate --typescript`

### Describe what you want

I'd love to see support for migrations in TypeScript. It would make life so much easier.

After we do a schema migration, we often need to migrate data too. This usually involves:

1. Selecting the data
2. Preparing it
3. Inserting or updating it

Sure, you can do this with plain SQL, but it’s not as simple or nice as writing a script in TypeScript.

Right now, we have to create a TypeScript script and run it manually, which is a pain because:

- **Manual Work:** Running scripts manually is prone to mistakes and is just extra work. It’s easy to mess up the order or the environment, especially with a team.

- **CI/CD Hassles:** Our CI/CD setup doesn’t handle these scripts automatically. We have to apply every migration by hand, which breaks the smooth automation we’re aiming for.

- **Tracking Issues:** Unlike schema migrations, these scripts don’t get tracked automatically, so we lose the history of what’s been applied. This can lead to inconsistent environments.

drizzle-kit already does a great job tracking and running schema migrations. It would be awesome if it could handle data migrations too, making the whole process smoother and less error-prone.