What API extensions can be called from storefront settings for orders

Specify the API extension point classes for: 1. Canceling a placed order. By default, B2B Commerce calls ccrz.cc_api_OutboundOrderCancel. 2. Extending order behavior that ccrz.cc_hk_Order executes. 3. Extending subscriptions behavior that ccrz.cc_hk_Subscriptions executes. 4. Extending effective accounts behavior that ccrz.cc_hk_EffectiveAccount executes. 5. Extending invoice behavior that ccrz.cc_hk_Invoice executes.