Clean up headers

src/classification/ConvexHull1D.hpp

src/classification/LPWrapper.hpp

src/classification/SVMWrapper.hpp

src/descriptor_identifier/Model/Model.hpp

src/descriptor_identifier/Model/ModelClassifier.hpp

src/descriptor_identifier/Model/ModelRegressor.hpp

src/descriptor_identifier/SISSO_DI/SISSOClassifier.hpp

src/descriptor_identifier/SISSO_DI/SISSORegressor.hpp

src/descriptor_identifier/SISSO_DI/SISSO_DI.hpp

src/feature_creation/feature_space/FeatureSpace.hpp

src/feature_creation/node/FeatureNode.hpp

src/feature_creation/node/ModelNode.hpp

src/feature_creation/node/Node.hpp

src/feature_creation/node/operator_nodes/OperatorNode.hpp

src/feature_creation/node/operator_nodes/allowed_ops.hpp

src/feature_creation/node/utils.hpp

src/feature_creation/units/Unit.hpp

src/inputs/InputParser.hpp

src/loss_function/LossFunctionConvexHull.hpp

src/loss_function/LossFunctionPearsonRMSE.hpp