Builder's QOL Shaders

* All: Lightning now illuminates the clouds (Iris only).
* All: Changed overworld fog density curve, and added a new config option to control part of it.
* All: Wet dirt now affects coarse dirt, rooted dirt, and podzol.
* All: Added waving leaves support for azalea and mangrove leaves.
* All: Added sliders for sky and horizon saturation in the overworld.
* All: Added support for the darkness effect.