Introduce ColorManager component
This change introduces a new component - ColorManager that is responsible for color management stuff. At the moment, it's very naive. It is useful only for updating gamma ramps. But in the future, it will be extended with more CMS-related features. The ColorManager depends on lcms2 library. This is an optional dependency. If lcms2 is not installed, the color manager won't be built. This also fixes the issue where colord and nightcolor overwrite each other's gamma ramps. With this change, the ColorManager will resolve the conflict between two.