Correctly attach root view recognizer in modals on iOS (#2498)

## Description

On iOS, the conditions to attach `RootViewGestureRecognizer` were
satisfied neither on the new nor the old architecture.
This PR changes this logic:
- unifies extracting the RN's touch handler to simply loop on all
recognizers attached to the root view, as it works in every case
- adds a check for `ModalHostViewController` when attaching the root
view recognizer and if the view is in the modal the logic is different:
- on the old arch:
[RCTModalHostView](https://github.com/facebook/react-native/blob/b50874cad41f06519a263fa53d15f76c836fd167/packages/react-native/React/Views/RCTModalHostView.m#L95-L100)
has a `UIView` as its child, and this one may only have one `RCTView` as
its child - this one has the `RCTTouchHandler` recognizer attached
- on the new arch:
[RCTFabricModalHostViewController](https://github.com/facebook/react-native/blob/b50874cad41f06519a263fa53d15f76c836fd167/packages/react-native/React/Fabric/Mounting/ComponentViews/Modal/RCTFabricModalHostViewController.mm#L42)
directly attaches `RCTSurfaceTouchHandler` to its direct subview

Fixes
#2487.

## Test plan

Tested on Example and FabricExample apps and on the code from the issue.

---------

Co-authored-by: Tomek Zawadzki <tomekzawadzki98@gmail.com>

ios/RNGestureHandlerManager.mm

@@ -3,6 +3,7 @@
 #import <React/RCTComponent.h>
 #import <React/RCTEventDispatcher.h>
 #import <React/RCTLog.h>
+#import <React/RCTModalHostViewController.h>
 #import <React/RCTRootContentView.h>
 #import <React/RCTRootView.h>
 #import <React/RCTUIManager.h>
@@ -15,6 +16,7 @@
 #import "RNRootViewGestureRecognizer.h"
 
 #ifdef RCT_NEW_ARCH_ENABLED
+#import <React/RCTFabricModalHostViewController.h>
 #import <React/RCTSurfaceTouchHandler.h>
 #import <React/RCTSurfaceView.h>
 #import <React/RCTViewComponentView.h>
@@ -199,15 +201,26 @@ - (void)registerViewWithGestureRecognizerAttachedIfNeeded:(UIView *)childView
 #ifdef RCT_NEW_ARCH_ENABLED
  UIView *touchHandlerView = childView;
 
- while (touchHandlerView != nil && ![touchHandlerView isKindOfClass:[RCTSurfaceView class]]) {
- touchHandlerView = touchHandlerView.superview;
+ if ([[childView reactViewController] isKindOfClass:[RCTFabricModalHostViewController class]]) {
+ touchHandlerView = [childView reactViewController].view;
+ } else {
+ while (touchHandlerView != nil && ![touchHandlerView isKindOfClass:[RCTSurfaceView class]]) {
+ touchHandlerView = touchHandlerView.superview;
+ }
  }
 #else
- UIView *parent = childView;
- while (parent != nil && ![parent respondsToSelector:@selector(touchHandler)])
- parent = parent.superview;
+ UIView *touchHandlerView = nil;
+
+ if ([[childView reactViewController] isKindOfClass:[RCTModalHostViewController class]]) {
+ touchHandlerView = [childView reactViewController].view.subviews[0];
+ } else {
+ UIView *parent = childView;
+ while (parent != nil && ![parent respondsToSelector:@selector(touchHandler)]) {
+ parent = parent.superview;
+ }
 
- UIView *touchHandlerView = [[parent performSelector:@selector(touchHandler)] view];
+ touchHandlerView = [[parent performSelector:@selector(touchHandler)] view];
+ }
 #endif // RCT_NEW_ARCH_ENABLED
 
  if (touchHandlerView == nil) {
@@ -247,20 +260,19 @@ - (void)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer
  if ([gestureRecognizer.view isKindOfClass:[UIScrollView class]])
  return;
 
-#ifdef RCT_NEW_ARCH_ENABLED
  UIGestureRecognizer *touchHandler = nil;
 
- // touchHandler (RCTSurfaceTouchHandler) is private in RCTFabricSurface so we have to do
- // this little trick to get access to it
+ // this way we can extract the touch handler on both architectures relatively easily
  for (UIGestureRecognizer *recognizer in [viewWithTouchHandler gestureRecognizers]) {
+#ifdef RCT_NEW_ARCH_ENABLED
  if ([recognizer isKindOfClass:[RCTSurfaceTouchHandler class]]) {
+#else
+ if ([recognizer isKindOfClass:[RCTTouchHandler class]]) {
+#endif // RCT_NEW_ARCH_ENABLED
  touchHandler = recognizer;
  break;
  }
  }
-#else
- RCTTouchHandler *touchHandler = [viewWithTouchHandler performSelector:@selector(touchHandler)];
-#endif // RCT_NEW_ARCH_ENABLED
  [touchHandler setEnabled:NO];
  [touchHandler setEnabled:YES];
 }