Bundle component selections for this order item. Required when ordering a bundle product. Each selection maps a bundle template component to the chosen product code. Obtain component IDs from the GetBundleComponentsAsync API method. When provided for a bundle product and the PostOrderApiBundleSupport feature flag is enabled, the server generates parent and child order items automatically. The server may also add zero-priced child order items for required products that are missing (see ApiBundleTemplate.ProductDependencies), evaluated separately for each bundle instance. When the feature flag is disabled, this field is ignored and the bundle product is treated as a regular item.