Allow retardance ceiling to be an optical config parameter

[gschlafly]

For example, for the spicule, experimental parameter of 150 nm was used to prepare the LC-PolScope images. Currently, the method of using the images is

# Prepare the retardance and azimuth images
ret_image_meas, azim_image_meas = prepare_ret_azim_images(
    ret_image_path, azim_image_path, 150, optical_info["wavelength"]
)