core/io
File handling APIs are typically considered part of I/O, and we did have most `FileAccess` implementations in `core/io` already.
* GIProbe is now VoxelGI * BakedLightmap is now LightmapGI As godot adds more ways to provide GI (as an example, SDFGI in 4.0), the different techniques (which have different pros/cons) need to be properly named to avoid confusion.