implement account-tied carts and cart reconciliation

Signed-off-by: Loan Laux <loan@outgrow.io>

framework/reactioncommerce/utils/mutations/reconcile-carts.ts

@@ -0,0 +1,13 @@
+import { cartPayloadFragment } from '@framework/utils/queries/get-checkout-query'
+
+const reconcileCartsMutation = `
+  mutation reconcileCartsMutation($input: ReconcileCartsInput!) {
+    reconcileCarts(input: $input) {
+      cart {
+        ${cartPayloadFragment}
+      }
+    }
+  }
+`
+
+export default reconcileCartsMutation