Prismarine Shader

Features added/changed:
+ Better volumetric clouds. They got nicer shape and more configuration. Still WIP though
+ Better planar clouds. They're also enabled by default now
+ Better water absorption and caustics
+ Nicer exponential fog. Still not nearly as good as it was in stage 4
+ New water normals
+ Improved underwater fog
+ Better water color
+ Stronger water reflections. There's a slider that controls their intensity now
+ As always, a whole bunch of small tweaks and improvements :>
+ probably smth else i forgor

Features fixed:
Fixed composite6 error
Fixed broken looking SSPT
Water reflections are no longer broken when absorption is enabled
Fixed water absorption looking bad when caustics are enabled, mentioned above

Features removed:
-