Describe the feature

Surface Rules make custom world generation possible with data packs in versions 1.18.2 and beyond.
However, the toolbox of rules and conditions that Minecraft provides are severely limiting in capability.
For instance, there's no way to use 3d noise, access multinoise parameters like rainfall and peak-valley, choose randomly from a weighted list of options, or even check whether a block is exposed to air.

Having the ability to register new surface rules and conditions would enable vastly more powerful custom terrain generation.

Specifically, the two objects that I'd love to have builders for are:
net.minecraft.world.level.levelgen.SurfaceRules.Condition
net.minecraft.world.level.levelgen.SurfaceRules.SurfaceRule

Many thanks!

Additional info

No response