[#276] Recover code from manual merge + change property name

* Change property name from `isMonitoringGroupFlag` to just
  `monitoringGroup`
* This is a breaking change but the code has not been deployed, just in
  dev testing instance
* The Java convention is to use `isMonitoringGroup` for the getter in a
  boolean property, but the BeanUtils.copyProperties we're using (from
  Spring), is not able to detect the getter and just skips the property,
  when marshalling from the Dto to the domain object. That's why we have
  a getMonitoringGroup instead.