Update tests for Label Statistics refactoring

The manually written tests needed to be updated to the new interface
and the lack of MeasurementMaps. Additionally, there are some methods
that are not yet implemented that still need to be implemented these
are just commented out until implemented.

Change-Id: Iaa1ff80ab0778613f83666679bec760863b02476
Merge topic 'SIMPLEITK-490_Uset1functionForLabelStatisticsImageFilter' into next

6d2d9fbd Update tests for Label Statistics refactoring