Instance tables refactor part 1: wrap graphical data in the new Instances<T> struct (#2230)

* Port VectorData to Instances<VectorData>

* Port ImageFrame<P> and TextureFrame to Instances<ImageFrame<P>> and Instances<TextureFrame>

* Avoid mutation with the TransformMut trait

* Port GraphicGroup to Instances<GraphicGroup>

* It compiles!

* Organize debugging

* Document upgrading

* Fix Brush node

* Restore TransformMut in lieu of TransformSet trait

* Fix tests

* Final code review

node-graph/gcore/src/application_io.rs

@@ -1,3 +1,4 @@
+use crate::instances::Instances;
 use crate::text::FontCache;
 use crate::transform::{Footprint, Transform, TransformMut};
 use crate::vector::style::ViewMode;
@@ -64,6 +65,8 @@ impl Size for web_sys::HtmlCanvasElement {
 	}
 }
 
+pub type TextureFrameTable = Instances<TextureFrame>;
+
 #[derive(Debug, Clone)]
 pub struct TextureFrame {
 	#[cfg(feature = "wgpu")]