CmdPal: Add keyboard shortcut (Ctrl+,) to open Settings (#42787)

## Summary of the Pull Request

This PR introduces a new keyboard shortcut `Ctrl + ,` that opens the
Settings window directly.


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## PR Checklist

- [x] Closes: #42785 
- [ ] **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

src/modules/cmdpal/Microsoft.CmdPal.UI/Pages/ShellPage.xaml.cs

@@ -591,17 +591,22 @@ public sealed partial class ShellPage : Microsoft.UI.Xaml.Controls.Page,
                          InputKeyboardSource.GetKeyStateForCurrentThread(VirtualKey.RightWindows).HasFlag(CoreVirtualKeyStates.Down);
 
         var onlyAlt = altPressed && !ctrlPressed && !shiftPressed && !winPressed;
-        if (e.Key == VirtualKey.Left && onlyAlt)
+        var onlyCtrl = !altPressed && ctrlPressed && !shiftPressed && !winPressed;
+        switch (e.Key)
         {
+            case VirtualKey.Left when onlyAlt: // Alt+Left arrow
                 WeakReferenceMessenger.Default.Send<NavigateBackMessage>(new());
                 e.Handled = true;
-        }
-        else if (e.Key == VirtualKey.Home && onlyAlt)
-        {
+                break;
+            case VirtualKey.Home when onlyAlt: // Alt+Home
                 WeakReferenceMessenger.Default.Send<GoHomeMessage>(new(WithAnimation: false));
                 e.Handled = true;
-        }
-        else
+                break;
+            case (VirtualKey)188 when onlyCtrl: // Ctrl+,
+                WeakReferenceMessenger.Default.Send<OpenSettingsMessage>(new());
+                e.Handled = true;
+                break;
+            default:
             {
                 // The CommandBar is responsible for handling all the item keybindings,
                 // since the bound context item may need to then show another
@@ -609,6 +614,8 @@ public sealed partial class ShellPage : Microsoft.UI.Xaml.Controls.Page,
                 TryCommandKeybindingMessage msg = new(ctrlPressed, altPressed, shiftPressed, winPressed, e.Key);
                 WeakReferenceMessenger.Default.Send(msg);
                 e.Handled = msg.Handled;
+                break;
+            }
         }
     }
 

src/modules/cmdpal/Microsoft.CmdPal.UI/Strings/en-us/Resources.resw

@@ -471,4 +471,7 @@ Right-click to remove the key combination, thereby deactivating the shortcut.</v
   <data name="ScreenReader_Announcement_NavigatedToPage0" xml:space="preserve">
     <value>Navigated to {0} page</value>
   </data>
+  <data name="SettingsButton.[using:Microsoft.UI.Xaml.Controls]ToolTipService.ToolTip" xml:space="preserve">
+    <value>Settings (Ctrl+,)</value>
+  </data>
 </root>