ENH: update classifiers to new base class MachineLearningModel

...earning/Supervised/include/otbBoostMachineLearningModel.h

...rning/Supervised/include/otbBoostMachineLearningModel.txx

.../Supervised/include/otbDecisionTreeMachineLearningModel.h

...upervised/include/otbDecisionTreeMachineLearningModel.txx

...ised/include/otbGradientBoostedTreeMachineLearningModel.h

...ed/include/otbGradientBoostedTreeMachineLearningModel.txx

...rvised/include/otbKNearestNeighborsMachineLearningModel.h

...ised/include/otbKNearestNeighborsMachineLearningModel.txx

...arning/Supervised/include/otbLibSVMMachineLearningModel.h

...ning/Supervised/include/otbLibSVMMachineLearningModel.txx

...Supervised/include/otbNeuralNetworkMachineLearningModel.h

...pervised/include/otbNeuralNetworkMachineLearningModel.txx

...g/Supervised/include/otbNormalBayesMachineLearningModel.h

...Supervised/include/otbNormalBayesMachineLearningModel.txx

...Supervised/include/otbRandomForestsMachineLearningModel.h

...pervised/include/otbRandomForestsMachineLearningModel.txx

.../Learning/Supervised/include/otbSVMMachineLearningModel.h

...earning/Supervised/include/otbSVMMachineLearningModel.txx