Instance tables refactor part 4: replace ArtboardGroups with multi-row Instances<Artboard> (#2265)

* Clean up dyn_any usages

* Migrate ArtboardGroup to ArtboardGroupTable (not yet flattened)

* Reorder graphical data imports

* Flatten and remove ArtboardGroup in favor of ArtboardGroupTable

* Fix test

node-graph/gpu-executor/src/lib.rs

@@ -1,8 +1,8 @@
-use dyn_any::{StaticType, StaticTypeSized};
 use graphene_core::raster::{color::RGBA16F, Image, Pixel, SRGBA8};
 use graphene_core::*;
 
 use bytemuck::{Pod, Zeroable};
+use dyn_any::{StaticType, StaticTypeSized};
 use glam::UVec3;
 use std::borrow::Cow;