**What**
- Fixes an issue where the admin dashboard would send region prices for deleted regions.
- Also, includes the implementation for `GET /admin/shipping-options/:id` and its corresponding SDK function.
**Why**
- When a region price for a deleted region was sent to the backend it would result in the insert hitting a not null constraint on the currency_code for prices. To avoid this the dashboard should not send region prices for deleted regions.
**Additional context**
- Prices for deleted regions should ideally not be returned when fetching shipping option prices. However, we don't yet have a mechanism for cleaning up region prices after a region is deleted.
Fixes CC-540
