fix(iOS): file picker crash (#1567)

* fix(iOS): Consider UIImagePickerController or similar controllers that are no longer beingPresented when acquiring the TopViewController; this prevents the crash of throwing an alert on a ViewController which is no longer in the window hierarchy

* fix(iOS): correcting import to src from lib

* fix(iOS): reverting import modification

Co-authored-by: Thibault Malbranche <thibault.malbranche@epitech.eu>

apple/RNCWebView.m

  */
 -(UIViewController *)topViewControllerWithRootViewController:(UIViewController *)viewController{
   if (viewController==nil) return nil;
-  if (viewController.presentedViewController!=nil) {
+  if (viewController.presentedViewController!=nil && viewController.presentedViewController.isBeingPresented) {
     return [self topViewControllerWithRootViewController:viewController.presentedViewController];
   } else if ([viewController isKindOfClass:[UITabBarController class]]){
     return [self topViewControllerWithRootViewController:[(UITabBarController *)viewController selectedViewController]];