- Implement `prefetch_related(...)` method on JSONAPIManager
- It was not implemented
- It is meant to prevent n+1 issue on cache querying
- Add optional parameter `prefetch_related` to method `get_many(...)` of JSONAPIModel
- It is meant to prevent n+1 issue on cache querying
- Improve `prefetch_jsonapi` method used in `WithJSONApiQuerySet`
- Now bears nested jsonapi prefetch
- It is meant to prevent n+1 issue on cache querying