fix(trimmer): Fix IL3050 warnings around Enum use

When building `src/Uno.UI` with trimmer warnings enabled (and turned up to 11):

	dotnet build  src/Uno.UI/Uno.UI.Skia.csproj -bl \
	  -p:TrimmerSingleWarn=false -p:_ExtraTrimmerArgs=--verbose -p:IsTrimmable=true -p:IsAotCompatible=true

One of the warnings is:

	src/Uno.UI/UI/Xaml/Internal/InputManager.Pointers.ManagedDirectManip.cs(365,42): error IL3050:
	  Using member 'System.Enum.GetValues(Type)' which has 'RequiresDynamicCodeAttribute' can break functionality when AOT compiling.
	  It might not be possible to create an array of the enum type at runtime.
	  Use the GetValues<TEnum> overload or the GetValuesAsUnderlyingType method instead.

Replace use of `System.Enum` methods which take a `Type` parameter
with their generic method overload:

  * `Enum.GetName(typeof(T), v)` becomes `Enum.GetName((T)v)`
  * `Enum.GetNames(typeof(T))` becomes `Enum.GetNames<T>()`
  * `Enum.GetValues(typeof(T))` becomes `Enum.GetValues<T>()`
  * `Enum.IsDefined(typeof(T), v)` becomes `Enum.IsDefined((T)v)`
  * `Enum.Parse(typeof(T), v)` becomes `Enum.Parse<T>(v)`

This fixes the IL3050 warnings.

Author: jonpryor

src/SamplesApp/SamplesApp.UITests/Windows_UI_Xaml_Media/ImageBrushTests/ImageBrush_Shape_Fill_StretchAndAlignment.cs

@@ -48,7 +48,7 @@ public void When_StretchAndAlignment([Values] Stretch stretch)
 
 					var greenContainer = _app.GetPhysicalRect("GreenBackground");
 
-					var permutation = $"{expected.Size.Width}-{expected.Size.Height}-{Enum.GetName(typeof(Stretch), expected.Stretch)}-X{Enum.GetName(typeof(AlignmentX), expected.AlignmentX)}-Y{Enum.GetName(typeof(AlignmentY), expected.AlignmentY)}";
+					var permutation = $"{expected.Size.Width}-{expected.Size.Height}-{Enum.GetName<Stretch>(expected.Stretch)}-X{Enum.GetName<AlignmentX>(expected.AlignmentX)}-Y{Enum.GetName<AlignmentY>(expected.AlignmentY)}";
 					using var snapshot = TakeScreenshot($"ImageBrush-{permutation}");
 
 					ImageAssert.HasPixels(

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/Common/NavigationViewCompactPaneLengthTestPage.xaml.cs

@@ -53,7 +53,7 @@ private void PaneToggleButtonVisiblityCheckbox_Unchecked(object sender, RoutedEv
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			NavView.PaneDisplayMode = mode;
 		}
 

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/Common/NavigationViewPage.xaml.cs

@@ -178,7 +178,7 @@ private void TestPage_Loaded(object sender, RoutedEventArgs e)
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			NavView.PaneDisplayMode = mode;
 		}
 

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/CustomResources/NavigationViewCustomThemeResourcesPage.xaml.cs

@@ -66,7 +66,7 @@ private void ExpandedModeCombobox_SelectionChanged(object sender, SelectionChang
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			NavView.PaneDisplayMode = mode;
 		}
 

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/Hierarchical/HierarchicalNavigationViewDataBinding.xaml.cs

@@ -147,7 +147,7 @@ private void OnItemCollapsed(object sender, NavigationViewItemCollapsedEventArgs
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			navview.PaneDisplayMode = mode;
 		}
 	}

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/Hierarchical/HierarchicalNavigationViewMarkup.xaml.cs

@@ -121,7 +121,7 @@ private void OnItemCollapsed(object sender, NavigationViewItemCollapsedEventArgs
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			navview.PaneDisplayMode = mode;
 		}
 

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NavigationViewTests/TopMode/NavigationViewTopNavOnlyPage.xaml.cs

@@ -59,7 +59,7 @@ public NavigationViewTopNavOnlyPage()
 		private void PaneDisplayModeCombobox_SelectionChanged(object sender, SelectionChangedEventArgs e)
 		{
 			var tag = Convert.ToString(((sender as ComboBox).SelectedItem as ComboBoxItem).Tag);
-			var mode = (NavigationViewPaneDisplayMode)Enum.Parse(typeof(NavigationViewPaneDisplayMode), tag);
+			var mode = Enum.Parse<NavigationViewPaneDisplayMode>(tag);
 			NavView.PaneDisplayMode = mode;
 		}
 

src/SamplesApp/UITests.Shared/Microsoft_UI_Xaml_Controls/NumberBoxTests/NumberBoxPage.xaml.cs

@@ -34,7 +34,7 @@ sender is ComboBox comboBox &&
 				comboBox.SelectedItem is ComboBoxItem item)
 			{
 				var scopeName = new InputScopeName();
-				scopeName.NameValue = (InputScopeNameValue)Enum.Parse(typeof(InputScopeNameValue), item.Content?.ToString() ?? string.Empty, true);
+				scopeName.NameValue = Enum.Parse<InputScopeNameValue>(item.Content?.ToString() ?? string.Empty, true);
 
 				var scope = new InputScope();
 				scope.Names.Add(scopeName);

src/SamplesApp/UITests.Shared/Windows_Storage/StorageFolderOperationsTests.xaml.cs

@@ -71,7 +71,7 @@ public string ErrorMessage
 		}
 
 		public CreationCollisionOption[] CreationCollisionOptions { get; } =
-			Enum.GetValues(typeof(CreationCollisionOption)).OfType<CreationCollisionOption>().ToArray();
+			Enum.GetValues<CreationCollisionOption>();
 
 		public CreationCollisionOption SelectedCreationCollisionOption
 		{

src/SamplesApp/UITests.Shared/Windows_UI_Core/SetCursor.xaml.cs

@@ -42,7 +42,7 @@ private void OnUnLoaded(object sender, RoutedEventArgs e)
 		private void InitList()
 		{
 #if !__ANDROID__ && !__APPLE_UIKIT__
-			var _enumval = Enum.GetValues(typeof(global::Windows.UI.Core.CoreCursorType));
+			var _enumval = Enum.GetValues<global::Windows.UI.Core.CoreCursorType>();
 			Box.ItemsSource = _enumval;
 			Box.SelectedIndex = 0;