Expose 2 more functions as autoloads:
csapprox#common#color_name_to_hex(name)
- Resolve a color name (like PapayaWhip) to hex (#ffefd5)
csapprox#common#hex_to_rgb(hex)
- Split a hex color (like #ffefd5) to a list ([ 255, 239, 213 ])
Not useful to keep it in one file anymore, since we already rely upon
multiple, and this will make later extending easier by giving us some
library functions for approximators.