Use group icon for components created by grouping. (#10020)

Use `group` icon for components created by grouping.

https://github.com/enso-org/enso/assets/1047859/50a0dbb6-d36e-4fcb-9f39-b6493b8cca86

See: #9831.

# Important Notes
- This PR always sets the icon, but it is not always shown due to missing updates from the backend; this issue is currently being investigated.

app/gui2/src/components/GraphEditor/collapsing.ts

@@ -214,7 +214,8 @@ export function performCollapse(
   }
   const argNames = info.extracted.inputs
   const collapsedFunction = Ast.Function.fromStatements(edit, collapsedName, argNames, collapsed)
-  topLevel.insert(posToInsert, collapsedFunction, undefined)
+  const collapsedFunctionWithIcon = Ast.Documented.new('ICON group', collapsedFunction)
+  topLevel.insert(posToInsert, collapsedFunctionWithIcon, undefined)
   return { refactoredNodeId, collapsedNodeIds, outputNodeId }
 }