[Cleaning] Remove any reference to grasping, which does not work

include/centroidal-dynamics-lib/centroidal_dynamics.hh

include/centroidal-dynamics-lib/util.hh

python/centroidal_dynamics_python.cpp

python/test/binding_tests.py

src/centroidal_dynamics.cpp

src/util.cpp

test/test_LP_solvers.cpp