[Windows] Subscribe less pointer events in `UpdatingGestureRecognizer…

…s` (#22781)

### Description of Change

The idea of the PR is simple. There two sets of pointer event
subscriptions:


https://github.com/dotnet/maui/blob/fcabff1fe3e551e22558cba74dd3a86e00323b69/src/Controls/src/Core/Platform/GestureManager/GesturePlatformManager.Windows.cs#L792-L796

and


https://github.com/dotnet/maui/blob/fcabff1fe3e551e22558cba74dd3a86e00323b69/src/Controls/src/Core/Platform/GestureManager/GesturePlatformManager.Windows.cs#L824-L827

Consequently, `_container.PointerPressed`, `_container.PointerExited`,
and `_container.PointerReleased` are subscribed twice. And this PR
removes these subscriptions.

 

### Performance impact

* MAIN:
[Maui.Controls.Sample.Sandbox.exe_20240601_222830.speedscope.MAIN.json](https://github.com/user-attachments/files/15523262/Maui.Controls.Sample.Sandbox.exe_20240601_222830.speedscope.MAIN.json)
* PR:
[Maui.Controls.Sample.Sandbox.exe_20240601_223130.speedscope.PR.json](https://github.com/user-attachments/files/15523263/Maui.Controls.Sample.Sandbox.exe_20240601_223130.speedscope.PR.json)


![image](https://github.com/dotnet/maui/assets/203266/fd77fd77-9c62-414f-b7a6-d9ceec6b3621)

-> ~25% improvement

### Issues Fixed

Contributes to #21787

src/Controls/src/Core/Platform/GestureManager/GesturePlatformManager.Windows.cs

@@ -363,9 +363,6 @@ void ClearContainerEventHandlers()
 					_container.ManipulationDelta -= OnManipulationDelta;
 					_container.ManipulationStarted -= OnManipulationStarted;
 					_container.ManipulationCompleted -= OnManipulationCompleted;
-					_container.PointerPressed -= OnPointerPressed;
-					_container.PointerExited -= OnPointerExited;
-					_container.PointerReleased -= OnPointerReleased;
 					_container.PointerCanceled -= OnPointerCanceled;
 				}
 			}
@@ -542,24 +539,45 @@ void OnPgrPointerEntered(object sender, PointerRoutedEventArgs e)
 					=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
 
 		void OnPgrPointerExited(object sender, PointerRoutedEventArgs e)
-			=> HandlePgrPointerEvent(e, (view, recognizer)
-				=> recognizer.SendPointerExited(view, (relativeTo)
-					=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+		{
+			HandlePgrPointerEvent(e, (view, recognizer)
+						=> recognizer.SendPointerExited(view, (relativeTo)
+							=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+
+			if ((_subscriptionFlags & SubscriptionFlags.ContainerManipulationAndPointerEventsSubscribed) != 0)
+			{
+				OnPointerExited(sender, e);
+			}
+		}
 
 		void OnPgrPointerMoved(object sender, PointerRoutedEventArgs e)
 			=> HandlePgrPointerEvent(e, (view, recognizer)
 				=> recognizer.SendPointerMoved(view, (relativeTo)
 					=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
 
 		void OnPgrPointerPressed(object sender, PointerRoutedEventArgs e)
-			=> HandlePgrPointerEvent(e, (view, recognizer)
-				=> recognizer.SendPointerPressed(view, (relativeTo)
-					=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+		{
+			HandlePgrPointerEvent(e, (view, recognizer)
+						=> recognizer.SendPointerPressed(view, (relativeTo)
+							=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+
+			if ((_subscriptionFlags & SubscriptionFlags.ContainerManipulationAndPointerEventsSubscribed) != 0)
+			{
+				OnPointerPressed(sender, e);
+			}
+		}
 
 		void OnPgrPointerReleased(object sender, PointerRoutedEventArgs e)
-			=> HandlePgrPointerEvent(e, (view, recognizer)
-				=> recognizer.SendPointerReleased(view, (relativeTo)
-					=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+		{
+			HandlePgrPointerEvent(e, (view, recognizer)
+						=> recognizer.SendPointerReleased(view, (relativeTo)
+							=> GetPosition(relativeTo, e), _control is null ? null : new PlatformPointerEventArgs(_control, e)));
+
+			if ((_subscriptionFlags & SubscriptionFlags.ContainerManipulationAndPointerEventsSubscribed) != 0)
+			{
+				OnPointerReleased(sender, e);
+			}
+		}
 
 		private void HandlePgrPointerEvent(PointerRoutedEventArgs e, Action<View, PointerGestureRecognizer> SendPointerEvent)
 		{
@@ -822,9 +840,6 @@ void UpdatingGestureRecognizers()
 			_container.ManipulationDelta += OnManipulationDelta;
 			_container.ManipulationStarted += OnManipulationStarted;
 			_container.ManipulationCompleted += OnManipulationCompleted;
-			_container.PointerPressed += OnPointerPressed;
-			_container.PointerExited += OnPointerExited;
-			_container.PointerReleased += OnPointerReleased;
 			_container.PointerCanceled += OnPointerCanceled;
 		}