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-rest/hawkbit-mgmt-api/src/main/java/org/eclipse/hawkbit/mgmt/json/model/action/MgmtActionStatus.java

@@ -33,7 +33,10 @@ public class MgmtActionStatus {
     private List<String> messages;
 
     @JsonProperty
-    private Long reportedAt;
+    private Long reportedAt;    
+    
+    @JsonProperty
+    private Integer code;
 
     /**
      * @return the statusId
@@ -95,4 +98,18 @@ public class MgmtActionStatus {
         this.reportedAt = reportedAt;
     }
 
+    /**
+     * @return the code
+     */
+    public Integer getCode() {
+        return code;
+    }
+
+    /**
+     * @param code
+     *            the reported code to set
+     */
+    public void setCode(final Integer code) {
+        this.code = code;
+    }
 }