REFAC: Rename Clustering to Unsupervised and update dependencies.

Modules/Applications/AppClassification/app/CMakeLists.txt

...ions/AppClassification/app/otbTrainImagesUnsupervised.cxx

...ions/AppClassification/app/otbTrainVectorUnsupervised.cxx

...plications/AppClassification/include/otbTrainImagesBase.h

Modules/Applications/AppClassification/otb-module.cmake

Modules/Applications/AppClassification/test/CMakeLists.txt

...Unsupervised/include/otbSharkKMeansMachineLearningModel.h

...supervised/include/otbSharkKMeansMachineLearningModel.txx

Modules/Learning/Unsupervised/otb-module.cmake

Modules/Learning/Unsupervised/test/CMakeLists.txt

...vised/test/otbMachineLearningUnsupervisedModelCanRead.cxx

...ervised/test/otbTrainMachineLearningUnsupervisedModel.cxx