-Removed normal/specular properties from nodes
-Create CanvasTexture, which can contain normal/specular channels
-Refactored, optimized and simplified 2D shaders
-Use atlas for light textures.
-Use a shadow atlas for shadow textures.
-Use both items aboves to make light rendering stateless (faster).
-Reorganized uniform sets for more efficiency.
It can be enabled in the Project Settings
(`rendering/quality/screen_filters/use_debanding`). It's disabled
by default as it has a small performance impact and can make
PNG screenshots much larger (due to how dithering works).
It will also slightly brighten the scene's dark areas.
As a result, it should be enabled only when banding is noticeable enough.
This closes#17006.
Which means that reduz' beloved style which we all became used to
will now be changed automatically to remove the first empty line.
This makes us lean closer to 1TBS (the one true brace style) instead
of hybridating it with some Allman-inspired spacing.
There's still the case of braces around single-statement blocks that
needs to be addressed (but clang-format can't help with that, but
clang-tidy may if we agree about it).
Part of #33027.
