Provide API method to signal process instance with correlationKey

   void signalProcessInstanceByCorrelationKey(String correlationKey, String signalName, Object event);
    void signalProcessInstanceByCorrelationKey(String deploymentId, String correlationKey, String signalName, Object event);   
    void signalProcessInstancesByCorrelationKeys(List<String> correlationKeys, String signalName, Object event);    
    void signalProcessInstancesByCorrelationKeys(String deploymentId, List<String> correlationKeys, String signalName, Object event);