CmdPal: Replace Tapped events with generic ones (#40640)

## Summary of the Pull Request
Click event on WinUI buttons handle more than just click and is more
versatile that Tapped event. When you tap a Button with a finger or
stylus, or press a left mouse button while the pointer is over it, the
button raises the Click event. If a button has keyboard focus, pressing
the Enter key or the Spacebar key also raises the Click event.

This PR also replaces the right-tapped event on items on the list page
with context menu handling, allowing other input gestures (such as
Shift+F10) to also display the context menu.

And finally, it adds a button to the status messages badge so that the
flyout can be opened using the keyboard.

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## PR Checklist

- [x] **Closes:** #40616 
- [ ] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [ ] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [ ] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

<!-- Provide a more detailed description of the PR, other things fixed,
or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

Tested on desktop with keyboard and mouse (no cats), and SB2 with touch
and pen. Input gestures seem to work as intended.

---------

Co-authored-by: Mike Griese <migrie@microsoft.com>

src/modules/cmdpal/Microsoft.CmdPal.UI/ExtViews/ListPage.xaml.cs

@@ -316,30 +316,51 @@ public sealed partial class ListPage : Page,
         return null;
     }
 
-    private void ItemsList_RightTapped(object sender, RightTappedRoutedEventArgs e)
+    private void ItemsList_OnContextRequested(UIElement sender, ContextRequestedEventArgs e)
     {
-        if (e.OriginalSource is FrameworkElement element &&
-            element.DataContext is ListItemViewModel item)
+        var (item, element) = e.OriginalSource switch
         {
-            if (ItemsList.SelectedItem != item)
-            {
-                ItemsList.SelectedItem = item;
-            }
+            // caused by keyboard shortcut (e.g. Context menu key or Shift+F10)
+            ListViewItem listViewItem => (ItemsList.ItemFromContainer(listViewItem) as ListItemViewModel, listViewItem),
 
-            ViewModel?.UpdateSelectedItemCommand.Execute(item);
+            // caused by right-click on the ListViewItem
+            FrameworkElement { DataContext: ListItemViewModel itemViewModel } frameworkElement => (itemViewModel, frameworkElement),
 
-            var pos = e.GetPosition(element);
+            _ => (null, null),
+        };
 
-            _ = DispatcherQueue.TryEnqueue(
-                () =>
-                    {
-                        WeakReferenceMessenger.Default.Send<OpenContextMenuMessage>(
-                            new OpenContextMenuMessage(
-                                element,
-                                Microsoft.UI.Xaml.Controls.Primitives.FlyoutPlacementMode.BottomEdgeAlignedLeft,
-                                pos,
-                                ContextMenuFilterLocation.Top));
-                    });
+        if (item == null || element == null)
+        {
+            return;
         }
+
+        if (ItemsList.SelectedItem != item)
+        {
+            ItemsList.SelectedItem = item;
+        }
+
+        ViewModel?.UpdateSelectedItemCommand.Execute(item);
+
+        if (!e.TryGetPosition(element, out var pos))
+        {
+            pos = new(0, element.ActualHeight);
+        }
+
+        _ = DispatcherQueue.TryEnqueue(
+            () =>
+            {
+                WeakReferenceMessenger.Default.Send<OpenContextMenuMessage>(
+                    new OpenContextMenuMessage(
+                        element,
+                        Microsoft.UI.Xaml.Controls.Primitives.FlyoutPlacementMode.BottomEdgeAlignedLeft,
+                        pos,
+                        ContextMenuFilterLocation.Top));
+            });
+        e.Handled = true;
+    }
+
+    private void ItemsList_OnContextCanceled(UIElement sender, RoutedEventArgs e)
+    {
+        _ = DispatcherQueue.TryEnqueue(() => WeakReferenceMessenger.Default.Send<CloseContextMenuMessage>());
     }
 }