Decouple BackDrop from modal (#32439)

* Create backdrop.js util

* revert breaking changes

remove PromiseTimout usage

revert class name

* one more test | change bundlewatch.config

* add config obj to backdrop helper | tests for rootElement | use transitionend helper

* Minor tweaks — Renaming

Co-authored-by: Rohit Sharma <rohit2sharma95@gmail.com>

js/src/util/index.js

@@ -230,6 +230,12 @@ const defineJQueryPlugin = (name, plugin) => {
   })
 }
 
+const execute = callback => {
+  if (typeof callback === 'function') {
+    callback()
+  }
+}
+
 export {
   getUID,
   getSelectorFromElement,
@@ -247,5 +253,6 @@ export {
   getjQuery,
   onDOMContentLoaded,
   isRTL,
-  defineJQueryPlugin
+  defineJQueryPlugin,
+  execute
 }