x and y should have different range when plot 3D fragilities

[longshuicy]

we might want to have x_start/x_end, y_start/y_end, x_interval/y_interval for the function

@staticmethod
    def get_x_y_z(curve, demand_type_names, curve_parameters, custom_curve_parameters, start=1, end=50,
                  sample_interval: int = 0.5):

But we need to think about backward compatibility