fix(@clayui/core): fixes error when having condition in the children …

…of TreeView.Item and TreeView.ItemStack the last element is positioned to the right

Using `React.Children.toArray` brings the result different from `React.Children.map`, apparently when you have conditionals, some elements are `Array<Array<any>>` while `React.Children.map` brings a flat array, we use `React.Children.count` because it is safer here and brings the exact count of elements as children.

packages/clay-core/src/tree-view/TreeViewItem.tsx

@@ -401,7 +401,7 @@ export function TreeViewItemStack({
 
 	const item = useItem();
 
-	const childrenArray = React.Children.toArray(children);
+	const childrenCount = React.Children.count(children);
 
 	const nestedChildren =
 		nestedKey && (item[nestedKey] as Array<Record<string, any>>);
@@ -503,9 +503,7 @@ export function TreeViewItemStack({
 				}
 
 				return (
-					<Layout.ContentCol
-						expand={index === childrenArray.length - 1}
-					>
+					<Layout.ContentCol expand={index === childrenCount - 1}>
 						{content}
 					</Layout.ContentCol>
 				);