ENH: Improve reading TerraSarX keywordlist

Testing/Code/IO/CMakeLists.txt

Testing/Code/IO/otbImageKeywordlist.cxx

Utilities/otbossimplugins/ossim/ossimTerraSarModel.cpp

Utilities/otbossimplugins/ossim/ossimTerraSarModel.h

Utilities/otbossimplugins/ossim/ossimTerraSarProductDoc.cpp

Utilities/otbossimplugins/ossim/ossimTerraSarProductDoc.h

Utilities/otbossimplugins/ossim/otb/ImageNoise.cpp

Utilities/otbossimplugins/ossim/otb/ImageNoise.h

Utilities/otbossimplugins/ossim/otb/Noise.cpp

Utilities/otbossimplugins/ossim/otb/Noise.h