Make test_tetrinria_core.c pass kwstyle script #23, fixed: code extraction in test_grid_new_destroy see assert_row_value, complete refactoring of test_grid_set_cells_with_piece simplification using trn_grid_equal, otherwise basic refactoring
Make test_tetrinria_core.c pass kwstyle script #23, fixed: code extraction in test_grid_new_destroy see assert_row_value, complete refactoring of test_grid_set_cells_with_piece simplification using trn_grid_equal, otherwise basic refactoring

sed-pro-inria/tetrinria,sed-pro-inria/tetrinria,sed-pro-inria/tetrinria