* Counting helpers for shipping rates and packages
* Use new helpers
* Make shipping calculator use shipping context directly
* Totals should use current address
* Avoid useShippingRates
* Return rates and other items from useShippingRatse in useStoreCart instead
* Update tests
* Merge conflict
* Merge conflict
* Make validation errors appear
* Make validation errors appear all at once
* Simplify diff
* Expose shippingErrorStatus from shipping context
* Memoize currentErrorStatus
* Pass currentErrorStatus to observers
* Add missing type-def property
* Fix typo in constant name
* Refactor emitEvent so false responses don't return true
* Make onCheckoutProcessing observers return errorMessage and validationErrors properties