Add cp, cf, x, y arrays in the available functions for optimization

Description of feature

Add the following slice data in the available function for optimization :
# "cp_visc_upper": viscous CP on the airfoil's upper surface
# "cp_invisc_upper": inviscid CP on the airfoil's upper surface
# "x_upper": x coordinates of the upper surface CP data
# "y_upper": y coordinates of the upper surface CP data
# "cp_visc_lower": viscous CP on the airfoil's lower surface
# "cp_invisc_lower": inviscid CP on the airfoil's lower surface
# "x_lower": x coordinates of the lower surface CP data
# "y_lower": y coordinates of the lower surface CP data
# "cf_upper": skin friction coefficient on the upper surface
# "x_cf_upper": x coordinates of upper surface skin friction coefficient
# "y_cf_upper": y coordinates of upper surface skin friction coefficient
# "cf_lower": skin friction coefficient on the lower surface
# "x_cf_lower": x coordinates of lower surface skin friction coefficient
# "y_cf_lower": y coordinates of lower surface skin friction coefficient
Thus we could optimize and constraint parameters available in this list (max pressure gradients for example)

Potential solution