[FEATURE]: precise migrations with code

### Feature hasn't been suggested before.

- [x] I have verified this feature I'm about to request hasn't been suggested before.

### Describe the enhancement you want to request

drizzle is great, it's dynamic design is perfect for my case.
(no need to putting all tables when initialization)

I wrote a wrapper for drizzle as a plugin for the framework I use.
But I need to do create table(migrations) while only know exactly one single table.

So use `pushSQLiteSchema({ table: ... })` will remove all other tables,
I try to use `generateSQLiteMigration()`,
but I didn't have value for the `prev` parameter in `generateSQLiteMigration()`,
because `sqlitePushIntrospect()` is not exported.

**TL;DR**
`pushSQLiteSchema()` needs all tables, otherwise other tables is gone.

`generateSQLiteMigration()` functions is exported, but can't call `sqlitePushIntrospect()` for `prev`

If I could access `sqlitePushIntrospect`,
I could filter out other tables and prevent accidentally removing other tables.