CmdPal: Using TitleBar (#41542)

## Summary of the Pull Request

Using TitleBar instead of custom XAML

<img width="1379" height="764" alt="image"
src="https://github.com/user-attachments/assets/cf2d4516-1566-4c3d-a4cf-e371d1ebe16d"
/>


## PR Checklist

- [x] Closes: #41414
- [x] **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

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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/Settings/SettingsWindow.xaml.cs

@@ -31,8 +31,10 @@ public sealed partial class SettingsWindow : WindowEx,
         this.InitializeComponent();
         this.ExtendsContentIntoTitleBar = true;
         this.SetIcon();
-        this.AppWindow.Title = RS_.GetString("SettingsWindowTitle");
+        var title = RS_.GetString("SettingsWindowTitle");
+        this.AppWindow.Title = title;
         this.AppWindow.TitleBar.PreferredHeightOption = TitleBarHeightOption.Tall;
+        this.TitleBar.Title = title;
         PositionCentered();
 
         WeakReferenceMessenger.Default.Register<NavigateToExtensionSettingsMessage>(this);