Since it only accepts power-of-two values, exposing it as an enum
makes more sense. This also allows for adding property hints to indicate
the performance cost of each value.
This also improves property hints for MSAA and FXAA.
Also implemented decal atlas, so projectors and other stuff can be added.
Sidenote: Had to make RID hashable, so some unrelated includes changed
in order to include it in hashfuncs.h
- Made shadow bias size independent, so it will remain when changing light or camera size.
- Implemented normal offset bias, which greatly enhances quality.
- Added transmission to subsurface scattering
- Reimplemented shadow filter modes
Closes#17260