Closure Excavator Example not using closures

[flbauer]

In the example excavator_rr.py closure groups are referring to geometric_XXX functions and not closure_XXX functions

Following modified functions will make the closure example work:
`def closure_q_to_a_group_1(state: Dict[str, float]):
nlp = {'x': closure_1_state[1:], 'f': c_1, 'p': closure_1_state[0]}
nlp_solver = casadi.nlpsol('q_to_a', 'ipopt', nlp, opts)
solution = nlp_solver(x0=[0, 0], p=[state['q_1']['ry']])
sol_vector = np.array(solution['x'])
return {'a_1': sol_vector[1]}

def closure_a_to_q_group_1(state: Dict[str, float]):
nlp = {'x': closure_1_state[:2], 'f': c_1, 'p': closure_1_state[2]}
nlp_solver = casadi.nlpsol('a_to_q', 'ipopt', nlp, opts)
solution = nlp_solver(x0=[0, 0], p=[state['a_1']])
sol_vector = np.array(solution['x'])
return {'q_1': {'ry': sol_vector[0]}}
...
def closure_q_to_a_group_2(state: Dict[str, float]):
nlp = {'x': closure_2_state[1:], 'f': c_2, 'p': closure_2_state[0]}
nlp_solver = casadi.nlpsol('q_to_a', 'ipopt', nlp, opts)
solution = nlp_solver(x0=[0, 0], p=[state['q_2']['ry']])
sol_vector = np.array(solution['x'])
return {'a_2': sol_vector[1]}

def closure_a_to_q_group_2(state: Dict[str, float]):
nlp = {'x': closure_2_state[:2], 'f': c_2, 'p': closure_2_state[2]}
nlp_solver = casadi.nlpsol('a_to_q', 'ipopt', nlp, opts)
solution = nlp_solver(x0=[0, 0], p=[state['a_2']])
sol_vector = np.array(solution['x'])
return {'q_2': {'ry': sol_vector[0]}}

closure_group_1 = KinematicGroup(name="geometric group 1",
virtual_chain=[virtual_joint_1, link_1],
actuated_state={'a_1': 0},
actuated_to_virtual=closure_a_to_q_group_1,
virtual_to_actuated=closure_q_to_a_group_1)

closure_group_2 = KinematicGroup(name="geometric group 2",
virtual_chain=[virtual_joint_2, link_2],
actuated_state={'a_2': 0},
actuated_to_virtual=closure_a_to_q_group_2,
virtual_to_actuated=closure_q_to_a_group_2,
parent=geometric_group_1)

`