Add P1 operators

operators-div_k_grad.toml

operators-terraneo.toml

operators/div_k_grad/CMakeLists.txt

...s/div_k_grad/P1ElementwiseDivKGradIcosahedralShellMap.cpp

...s/div_k_grad/P1ElementwiseDivKGradIcosahedralShellMap.hpp

...ply_P1ElementwiseDivKGradIcosahedralShellMap_macro_3D.cpp

...ues_P1ElementwiseDivKGradIcosahedralShellMap_macro_3D.cpp

...ply_P1ElementwiseDivKGradIcosahedralShellMap_macro_3D.cpp

...ues_P1ElementwiseDivKGradIcosahedralShellMap_macro_3D.cpp

...rix_P1ElementwiseDivKGradIcosahedralShellMap_macro_3D.cpp

operators/k_mass/CMakeLists.txt

operators/k_mass/P1ToP2ElementwiseKMass.cpp

operators/k_mass/P1ToP2ElementwiseKMass.hpp

...lementwiseKMass_apply_P1ToP2ElementwiseKMass_macro_2D.cpp

...lementwiseKMass_apply_P1ToP2ElementwiseKMass_macro_3D.cpp

...lementwiseKMass_apply_P1ToP2ElementwiseKMass_macro_2D.cpp

...lementwiseKMass_apply_P1ToP2ElementwiseKMass_macro_3D.cpp

...entwiseKMass_toMatrix_P1ToP2ElementwiseKMass_macro_2D.cpp

...entwiseKMass_toMatrix_P1ToP2ElementwiseKMass_macro_3D.cpp

operators/mass/CMakeLists.txt