[FEATURE]: Convert rows returned by `db.execute` from SQL column name to TypeScript column name

### 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

Let's say I have a table where a column whose SQL name and TS name are different

```ts
export const users = pgTable("users", {
userId: bigint("user_id", { mode: "number" }).notNull().primaryKey(),
};
```

If I query using Drizzle's normal `select` syntax

```ts
const data = await db.select().from(users);
console.log(data.at(0));
```

the column name in the returned object is `userId` as expected.

But if I query using raw SQL

```ts
const data = await db.execute(
sql`select * from "users" where "user_id" = ${userId}`,
);
console.log(data.rows.at(0));
```

the column name is `user_id`. Now this is still expected, after all I ran a raw query and should expect a raw SQL response. But I think it would be nice to have an utility function to help auto convert between the SQL values and the TS values so I don't have to manually do

```ts
return {
userId: Number(rawValue.user_id),
displayName: rawValue.display_name,
// ...
};
```

for every column in that table.

Start by tracing the db.execute raw-query path and the pgTable schema definitions shown in the issue, focusing on where SQL column names and TypeScript names are available. Done means a utility can convert returned raw rows using those mappings, including the example user_id to userId case, without requiring manual per-column objects.

Written by the indexing model from the issue text.