[dua] dua registration and re-registration (#5276)

- registration workflow framework
- registration and reregistration
- registration and reregistration on behalf of children
- add pseudo response status for test/certification purpose
- add unit test

include/openthread/backbone_router_ftd.h

@@ -174,6 +174,25 @@ void otBackboneRouterSetRegistrationJitter(otInstance *aInstance, uint8_t aJitte
  */
 otError otBackboneRouterGetDomainPrefix(otInstance *aInstance, otBorderRouterConfig *aConfig);
 
+/**
+ * This method configures response status for next DUA registration.
+ *
+ * Note: available only when `OPENTHREAD_CONFIG_REFERENCE_DEVICE_ENABLE` is enabled.
+ *       Only used for test and certification.
+ *
+ * TODO: (DUA) support coap error code and corresponding process for certification purpose.
+ *
+ * @param[in] aInstance A pointer to an OpenThread instance.
+ * @param[in] aMlIid    A pointer to the Mesh Local IID. If NULL, respond with @p aStatus for any
+ *                      coming DUA.req, otherwise only respond the one with matching @p aMlIid.
+ * @param[in] aStatus   The status to respond.
+ *
+ *
+ */
+void otBackboneRouterConfigNextDuaRegistrationResponse(otInstance *                    aInstance,
+                                                       const otIp6InterfaceIdentifier *aMlIid,
+                                                       uint8_t                         aStatus);
+
 /**
  * @}
  *

include/openthread/instance.h

@@ -53,7 +53,7 @@ extern "C" {
  * @note This number versions both OpenThread platform and user APIs.
  *
  */
-#define OPENTHREAD_API_VERSION (18)
+#define OPENTHREAD_API_VERSION (19)
 
 /**
  * @addtogroup api-instance