implemented shipping order dependency for shippings

__Tasks:__

- [x] implemented order dependency class 
- [x] function for count shippings by order id
- [ ] gather feedback

__Informations:__

| Q             | A
| ------------- | ---
| Tests pass?   | -
| Fixed tickets | -
| BC Breaks     | -
| Doc           | -

actually, yes. but currently it's not needed;