[789-deprecate-content-of-globaldefinitions] string -> std::string

FWI/src/FWIAbstractInterfaceDGTSVA.hpp

FWI/src/FWINonlinearSolvers.cpp

FWI/src/FWIRandomMains.cpp

FWI/src/FWI_DGTS.cpp

FWI/src/ForwardModels/ForwardModel.hpp

FWI/src/ForwardModels/ForwardModelCreator.hpp

FWI/src/Helper/FWIDataContainerDomain.cpp

FWI/src/Helper/FWIHelpers.cpp

FWI/src/Helper/FWIHelpers.hpp

FWI/src/Helper/FWIMppHelpers.cpp

FWI/src/Helper/NormCalculation.cpp

FWI/src/Helper/VTUModelReader.hpp

FWI/src/Problems/FWIInversionProblems.cpp

FWI/src/Problems/Sources/FWISourceWavelet.cpp

FWI/src/Problems/Sources/FWISourceWavelet.hpp

FWI/src/Problems/Sources/WaypointSources.hpp

FWI/src/Problems/WaveProblemFromImages2D.cpp

FWI/src/Problems/WaveProblemFromImages2D.hpp

TimeStepping/src/DGVAcousticPlotter.cpp