Make many arrays update correctly

At the moment, when `update` method is called in a many array, the record array implementation is taken, and this make the `adapter.findAll` be called. For example: `post.get('comments').update()` will send a request to `/comments`.

With this PR when a many array call update, is used `adapter.findMany` so a request is sent to `/comments?ids[]=1&ds[]=2&ds[]=3...`

In the case of a payload with links the `adapter.findHasMany` is used and a resquest is sent to `/post/1/comments`.

//cc @bradleypriest @sly7-7