[Settings] Add GPO control (#40256)

<!-- 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
Quality of (dev)life improvement: a dedicated control for showing the
GPO-warning InfoBar. As a result, we no longer need to copy-and-paste
the same InfoBar XAML all over the place, ensuring that things are
consistent and easier to maintain.

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## PR Checklist

- [x] **Closes:** #40252
- [ ] **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

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wherever possible, but list manual validation steps taken as well -->
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---------

Co-authored-by: Gordon Lam (SH) <yeelam@microsoft.com>
Co-authored-by: Gordon Lam <73506701+yeelam-gordon@users.noreply.github.com>

src/settings-ui/Settings.UI/SettingsXAML/Controls/GPOInfoControl.xaml

@@ -0,0 +1,28 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ResourceDictionary
+    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:local="using:Microsoft.PowerToys.Settings.UI.Controls">
+    <Style TargetType="local:GPOInfoControl">
+        <Setter Property="Template">
+            <Setter.Value>
+                <ControlTemplate TargetType="local:GPOInfoControl">
+                    <StackPanel Orientation="Vertical">
+                        <ContentPresenter Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}" />
+                        <InfoBar
+                            x:Uid="GPO_SettingIsManaged"
+                            Margin="0,4,0,0"
+                            IsClosable="False"
+                            IsOpen="{TemplateBinding ShowWarning}"
+                            IsTabStop="{TemplateBinding ShowWarning}"
+                            Severity="Informational">
+                            <InfoBar.IconSource>
+                                <FontIconSource FontFamily="{StaticResource SymbolThemeFontFamily}" Glyph="&#xE72E;" />
+                            </InfoBar.IconSource>
+                        </InfoBar>
+                    </StackPanel>
+                </ControlTemplate>
+            </Setter.Value>
+        </Setter>
+    </Style>
+</ResourceDictionary>

src/settings-ui/Settings.UI/SettingsXAML/Controls/GPOInfoControl.xaml.cs

@@ -0,0 +1,49 @@
+// Copyright (c) Microsoft Corporation
+// The Microsoft Corporation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices.WindowsRuntime;
+using Microsoft.UI.Xaml;
+using Microsoft.UI.Xaml.Controls;
+using Microsoft.UI.Xaml.Data;
+using Microsoft.UI.Xaml.Documents;
+using Microsoft.UI.Xaml.Input;
+using Microsoft.UI.Xaml.Media;
+
+namespace Microsoft.PowerToys.Settings.UI.Controls;
+
+public sealed partial class GPOInfoControl : ContentControl
+{
+    public static readonly DependencyProperty ShowWarningProperty =
+      DependencyProperty.Register(
+          nameof(ShowWarning),
+          typeof(bool),
+          typeof(GPOInfoControl),
+          new PropertyMetadata(false, OnShowWarningPropertyChanged));
+
+    public bool ShowWarning
+    {
+        get => (bool)GetValue(ShowWarningProperty);
+        set => SetValue(ShowWarningProperty, value);
+    }
+
+    private static void OnShowWarningPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+    {
+        if (d is GPOInfoControl gpoInfoControl)
+        {
+            if (gpoInfoControl.ShowWarning)
+            {
+                gpoInfoControl.IsEnabled = false;
+            }
+        }
+    }
+
+    public GPOInfoControl()
+    {
+        DefaultStyleKey = typeof(GPOInfoControl);
+    }
+}