[FEATURE]: Add support for prepared statements to the newly added `$count` API

### Describe what you want

Based on the below `$count` API first added with version [0.34.0](https://github.com/drizzle-team/drizzle-orm/releases/tag/0.34.0).
```typescript
// how many users with the name "Dan" are in the database
const count: number = await db.$count(users, eq(name, "Dan"));
```
I expected to be able to swap my current implementation of a prepared `count` statement from
```typescript
const statement = db.select({ count: sql`count(*)` }).from(users)
.where(eq(users.name, "Dan"))).prepare('UserService.GetAmountOfDans');
```
to
```typescript
const statement = db.$count(users, eq(users.name, "Dan")).prepare('UserService.GetAmountOfDans');
```
or with a placeholder
```typescript
const statement = db.$count(users, eq(users.name, sql.placeholder('name'))).prepare('UserService.GetAmountOfName');
```
However, doing either of these two results in the following error on the `prepare` method:
`Property 'prepare' does not exist on type 'PgCountBuilder>'.`