Bug fixes from the previous merge

src/feature_creation/feature_space/FeatureSpace.cpp

...s/allowed_operator_nodes/abs_diff/absolute_difference.cpp

...re_creation/node/value_storage/nodes_value_containers.hpp

src/mpi_interface/MPI_ops.cpp

src/utils/compare_features.cpp

src/utils/compare_features.hpp

src/utils/project.cpp

src/utils/project.hpp

tests/googletest/utils/test_compare_features.cc