in_app_purchase_storekit 0.3.0+3

An implementation for the iOS platform of the Flutter `in_app_purchase` plugin. This uses the StoreKit Framework.

0.3.0+3

• Implements transaction caching for StoreKit ensuring transactions are delivered to the Flutter client.

0.3.0+2

• Internal code cleanup for stricter analysis options.

0.3.0+1

• Removes dependency on meta.

0.3.0

• BREAKING CHANGE: InAppPurchaseStoreKitPlatform.restorePurchase() emits an empty instance of List<ProductDetails> when there were no transactions to restore, indicating that the restore procedure has finished.

0.2.1

• Renames in_app_purchase_ios to in_app_purchase_storekit to facilitate future macOS support.