feat(sdk): automatically fallback to generated types attempt (#15167)

### Before

You had to manually pass `GeneratedTypes` to the SDK:

```ts
import { PayloadSDK } from '@payloadcms/sdk'
import type { Config } from './payload-types'

const sdk = new PayloadSDK<Config>({})
```

### After

The SDK automatically uses your generated types via module augmentation
- just like the Payload Local API. If your project has a
`payload-types.ts`, the types are picked up automatically:

```ts
import { PayloadSDK } from '@payloadcms/sdk'

const sdk = new PayloadSDK({}) // Types inferred automatically
```

You can still pass a custom type if needed.

This PR also removes a lot of duplicated types between sdk and payload,
by allowing the payload types to accept an optional `TGeneratedTypes`
generic.