Implement JSON security context serializer (new default) - smaller info and human readable (#2652)

keeps backward compatibility by being able to fallback to JAVA_SERIALIZATION

+ fix DMF messages with status code

Signed-off-by: Avgustin Marinov <Avgustin.Marinov@bosch.com>

hawkbit-ddi/hawkbit-ddi-resource/src/test/java/org/eclipse/hawkbit/ddi/rest/resource/AbstractDDiApiIntegrationTest.java

@@ -80,7 +80,6 @@ public abstract class AbstractDDiApiIntegrationTest extends AbstractRestIntegrat
 
     protected static final int ARTIFACT_SIZE = 5 * 1024;
     private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper();
-    private static final Random RND = new Random();
 
     /**
      * Convert JSON to a CBOR equivalent.