Called if you have subscribed to continuous updates from the control thread, or if there is
data returned from the TRealtime counterpart.
This is guaranteed to be invoked before ProcessorInstance.IControl<T0>.Dispose if there's any data that's been sent
from ProcessorInstance.Pipe.SendData and suitable flags have been set in
ProcessorInstance.CreationParameters.controlUpdateSetting.
Additional resources: ControlContext.Manual.Update, ControlContext.UpdateSetting