[CmdPal] Settings UI polishing (#38094)

<!-- Enter a brief description/summary of your PR here. What does it fix/what does it change/how was it tested (even manually, if necessary)? -->
## Summary of the Pull Request

Settings window UI polishing:
- Make the navigation view toggle button move in the title bar when navigation view mode is compact or minimal
- Center settings card in the window
- Properly set windows icon in order to make it visible in task manager and task view

_main branch_
![image](https://github.com/user-attachments/assets/792f0779-016a-4056-81b0-04244d903909)

![image](https://github.com/user-attachments/assets/81ac2761-2a9c-4fe7-a122-2f69f900e656)

_PR_
![image](https://github.com/user-attachments/assets/029b95a0-9629-4732-9f0c-bf586954e887)

![image](https://github.com/user-attachments/assets/81bb2beb-9a07-42cf-8594-16ba5a9cda1b)

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## PR Checklist

- [ ] **Closes:**: https://github.com/zadjii-msft/PowerToys/issues/581

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Co-authored-by: Niels Laute <niels.laute@live.nl>

src/modules/cmdpal/Microsoft.CmdPal.UI/Settings/ExtensionsPage.xaml

@@ -19,8 +19,8 @@
             <RowDefinition Height="Auto" />
             <RowDefinition Height="*" />
         </Grid.RowDefinitions>
-        <ScrollViewer Grid.Row="1" Padding="0,0,8,0">
-            <Grid Padding="8,16,8,8">
+        <ScrollViewer Grid.Row="1">
+            <Grid Padding="16">
                 <StackPanel
                     MaxWidth="1000"
                     HorizontalAlignment="Stretch"