Check if box is opened in another isolate

**Is your feature request related to a problem? Please describe.**
I am doing background tasks via `workmanager` package. During the background task a code is running in a different dart isolate than the main isolate. To prevent errors, I would like to check in the background task if the app is open. If it is then I skip the background task.

**Describe the solution you'd like**
Something like an additional argument like `Hive.isBoxOpen('myBox', differentIsolate: true)`.

**Describe alternatives you've considered**
No Idea

**Version**
- Platform: iOS, Android, Mac, Windows, Linux, Web
- Flutter version: 1.22.4
- Hive version: 1.4.4