Change inconsistent course title / semester error to warning #187

src/data/nodes/student_data.cpp

src/data/nodes/student_data.hpp

src/model/input_model.cpp

src/util/strings.hpp

src/view/input_window/input_tab_csv_single_cohort.cpp

src/view/input_window/load_file_view.cpp

test/util/print_types.cpp