Rename the Group type to Graphic everywhere (#3009)

editor/src/messages/tool/tool_messages/artboard_tool.rs

@@ -339,7 +339,7 @@ impl Fsm for ArtboardToolFsmState {
 					responses.add(GraphOperationMessage::NewArtboard {
 						id,
 						artboard: Artboard {
-							group: Table::new(),
+							content: Table::new(),
 							label: String::from("Artboard"),
 							location: start.min(end).round().as_ivec2(),
 							dimensions: (start.round() - end.round()).abs().as_ivec2(),

editor/src/messages/tool/tool_messages/brush_tool.rs

@@ -163,8 +163,8 @@ impl LayoutHolder for BrushTool {
 
 		let blend_mode_entries: Vec<Vec<_>> = BlendMode::list()
 			.iter()
-			.map(|group| {
-				group
+			.map(|section| {
+				section
 					.iter()
 					.map(|blend_mode| {
 						MenuListEntry::new(format!("{blend_mode:?}"))

editor/src/messages/tool/tool_messages/gradient_tool.rs

@@ -674,6 +674,7 @@ mod test_gradient {
 		let folder = layers.next().unwrap();
 		let rectangle = layers.next().unwrap();
 		assert_eq!(rectangle.parent(metadata), Some(folder));
+
 		// Transform the group
 		editor
 			.handle_message(GraphOperationMessage::TransformSet {