The options object for the states changing. Structure:
metricSet [type: dundas.entities.MetricSet] - The metric set object that is the source of the metric set binding.
metricSetBinding [type: dundas.view.controls.MetricSetBinding] - The metric set binding that is related.
changedStateGroups [type: Array, elementType: dundas.data.StateGroup] - (optional) The state groups that have been added or had states added. If this is null, it's assumed to be all of them.
removedStateGroups [type: Array, elementType: dundas.data.StateGroup] - (optional) The state groups that have been deleted.