TEST: Add and update test for Unsupervised Image classification.

Modules/Learning/Unsupervised/otb-module.cmake

Modules/Learning/Unsupervised/test/CMakeLists.txt

...ervised/test/otbMachineLearningClusteringModelCanRead.cxx

...ed/test/otbSharkUnsupervisedImageClassificationFilter.cxx

...upervised/test/otbTrainMachineLearningClusteringModel.cxx

.../Learning/Unsupervised/test/otbUnsupervisedTestDriver.cxx

Modules/Learning/Unsupervised/test/tests-shark.cmake