fix(focus): [WASM] Adjust native focus application for TextBox

Apply focus directly to inner TextBoxView to prevent it from bouncing back and forth.

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBox.wasm.cs

@@ -10,9 +10,8 @@ public partial class TextBox : Control
 		private TextBoxView _textBoxView;
 
 		protected override bool IsDelegatingFocusToTemplateChild() => true; // _textBoxView
-		protected override bool RequestFocus(FocusState state) => FocusTextView();
 		partial void OnTextClearedPartial() => FocusTextView();
-		protected virtual bool FocusTextView() => FocusManager.FocusNative(_textBoxView);
+		internal bool FocusTextView() => FocusManager.FocusNative(_textBoxView);
 
 		private void UpdateTextBoxView()
 		{

src/Uno.UI/UI/Xaml/Input/FocusManager.wasm.cs

@@ -45,6 +45,11 @@ internal static bool FocusNative(UIElement element)
 				return false;
 			}
 
+			if (element is TextBox textBox)
+			{
+				return textBox.FocusTextView();
+			}
+
 			var command = $"Uno.UI.WindowManager.current.focusView({element.HtmlId});";
 			WebAssemblyRuntime.InvokeJS(command);