Deprecate channel publish, inventory adjust and add displayType

The inventoryAdjustQuantity mutation and its input and payload types are removed in favor of a bulk adjustment mutation, so apps should switch to inventoryAdjustQuantities immediately. Publishable resources no longer expose publishablePublishToCurrentChannel and publishableUnpublishToCurrentChannel; these are deprecated and replaced by publishablePublish and publishableUnpublish, which now handle channel operations at the root level. The AppInstallation type’s channel and publication fields become deprecated, guiding developers to use the new root-level channels and publications queries. Several Publishable and Product/Collection fields that referenced “CurrentPublication” are deprecated, with the recommendation to use publishedOnPublication or resourcePublications instead. DiscountCode variants now feature a slightly revised usageLimit description but maintain the same functionality. A new non‑nullable displayType field on ShopifyPaymentsBalanceTransaction provides a user‑friendly name for transaction types. Finally, two new enum values were added to ShopifyPaymentsTransactionType: MANAGED_MARKETS_NON_TARGET_REVENUE_ADJUSTMENT_PLATFORM_CREDIT and its reversal, expanding the set of recognizable transaction types.