KERNEL-14067 feat:checkbox的es6化

src/case/checkbox/index.js

@@ -0,0 +1,6 @@
+export { ArrowTreeGroupNodeCheckbox } from "./check.arrownode";
+export { CheckingMarkNode } from "./check.checkingmarknode";
+export { FirstTreeNodeCheckbox } from "./check.first.treenode";
+export { LastTreeNodeCheckbox } from "./check.last.treenode";
+export { MidTreeNodeCheckbox } from "./check.mid.treenode";
+export { TreeNodeCheckbox } from "./check.treenode";