REFAC: Use DEMHandler instead of OssimDEMHandler when possible

Modules/Adapters/OSSIMAdapters/include/otbDEMHandler.h

...Adapters/OSSIMAdapters/include/otbSarSensorModelAdapter.h

...es/Adapters/OSSIMAdapters/include/otbSensorModelAdapter.h

Modules/Adapters/OSSIMAdapters/otb-module.cmake

Modules/Adapters/OSSIMAdapters/src/CMakeLists.txt

Modules/Adapters/OSSIMAdapters/src/otbDEMHandler.cxx

Modules/Adapters/OSSIMAdapters/src/otbSensorModelAdapter.cxx

Modules/Adapters/OSSIMAdapters/test/otbDEMHandlerTest.cxx

...s/Adapters/OSSIMAdapters/test/otbRPCSolverAdapterTest.cxx

...lications/AppProjection/app/otbGenerateRPCSensorModel.cxx

...s/Applications/AppProjection/app/otbRefineSensorModel.cxx

Modules/Filtering/ImageManipulation/otb-module.cmake

...ering/Projection/test/otbGenericRSResampleImageFilter.cxx

...ring/Projection/test/otbGenericRSTransformGenericTest.cxx

...ing/Projection/test/otbTileImageFilterRSTransformTest.cxx

Modules/IO/IOGDAL/src/CMakeLists.txt

...stration/DisparityMap/test/otbDisparityMapToDEMFilter.cxx

...cationEngine/src/otbWrapperElevationParametersHandler.cxx