message: Add metafield on apply
diff: @@ -33,7 +33,10 @@ export interface PostPurchaseRenderApi
  changeset: Readonly<Changeset> | string,
  ): Promise<CalculateChangesetResult>;
  /** Requests a changeset to be applied to the initial purchase, and to charge the buyer with the difference in total price, if any. */
  - applyChangeset(changeset: string): Promise<ApplyChangesetResult>;
  + applyChangeset(
  + changeset: string,
  + orderMetafield?: Metafield,
  + ): Promise<ApplyChangesetResult>;
  /**
  * Indicates that the extension has finished running.
  * Currently, effectively redirects buyers to the thank you page.
  