feat(payment): add checkout locale to Stripe elements

Author: PavlenkoM

packages/core/src/cart/cart.ts

@@ -35,5 +35,5 @@ export default interface Cart {
     createdTime: string;
     updatedTime: string;
     source?: CartSource;
-    locale?: string;
+    locale: string;
 }

packages/core/src/cart/carts.mock.ts

@@ -26,6 +26,7 @@ export function getCart(): Cart {
         },
         createdTime: '2018-03-06T04:41:49+00:00',
         updatedTime: '2018-03-07T03:44:51+00:00',
+        locale: 'en',
     };
 }
 

packages/payment-integration-api/src/cart/cart.ts

@@ -20,4 +20,5 @@ export default interface Cart {
     createdTime: string;
     updatedTime: string;
     source?: CartSource;
+    locale: string;
 }

packages/payment-integrations-test-utils/src/test-utils/carts.mock.ts

@@ -30,6 +30,7 @@ export default function getCart(): Cart {
         },
         createdTime: '2018-03-06T04:41:49+00:00',
         updatedTime: '2018-03-07T03:44:51+00:00',
+        locale: 'en',
     };
 }