Introduce action status scoped custom code (#1277)

* Allow providing a custom code with an action status feedback to give more fine grained device specific details.
* Add ddi rest docs for new optional status code value.
* Provide new code value via mgmt api. Fix review findings.
* Fix failing tests

Signed-off-by: Michael Herdt <Michael.Herdt@bosch.io>
Co-authored-by: Stefan Behl <stefan.behl@bosch.io>

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/builder/ActionStatusCreate.java

@@ -37,6 +37,8 @@ public interface ActionStatusCreate {
      */
     ActionStatusCreate occurredAt(long occurredAt);
 
+    ActionStatusCreate code(int code);
+
     /**
      * @param messages
      *            for {@link ActionStatus#getMessages()}

hawkbit-repository/hawkbit-repository-api/src/main/java/org/eclipse/hawkbit/repository/model/ActionStatus.java

@@ -8,6 +8,7 @@
  */
 package org.eclipse.hawkbit.repository.model;
 
+import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 
 import org.eclipse.hawkbit.repository.model.Action.Status;
@@ -39,4 +40,6 @@ public interface ActionStatus extends TenantAwareBaseEntity {
      */
     Status getStatus();
 
+    Optional<Integer> getCode();
+
 }