[CmdPal][UT] Refactor some cmdpal ext's ut and improve the test case (#40896)

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fix/what does it change/how was it tested (even manually, if necessary)?
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## Summary of the Pull Request
1. Remove some AI generated nonsense case
2. Add ISettingsInterface for those ext for testing purpose.
3. Add query test.

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## PR Checklist

- [x] Closes: #40897
- [x] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [x] **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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---------

Co-authored-by: Yu Leng <yuleng@microsoft.com>

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Helpers/ISettingsInterface.cs

@@ -0,0 +1,17 @@
+// 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.Text;
+using System.Threading.Tasks;
+
+namespace Microsoft.CmdPal.Ext.Registry.Helpers;
+
+public interface ISettingsInterface
+{
+    // Add registry-specific settings methods here if needed
+    // For now, this can be empty if there are no settings for Registry
+}

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Helpers/SettingsManager.cs

@@ -0,0 +1,37 @@
+// 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.IO;
+using Microsoft.CommandPalette.Extensions.Toolkit;
+
+namespace Microsoft.CmdPal.Ext.Registry.Helpers;
+
+public class SettingsManager : JsonSettingsManager, ISettingsInterface
+{
+    private static readonly string _namespace = "registry";
+
+    private static string Namespaced(string propertyName) => $"{_namespace}.{propertyName}";
+
+    internal static string SettingsJsonPath()
+    {
+        var directory = Utilities.BaseSettingsPath("Microsoft.CmdPal");
+        Directory.CreateDirectory(directory);
+
+        // now, the state is just next to the exe
+        return Path.Combine(directory, "settings.json");
+    }
+
+    public SettingsManager()
+    {
+        FilePath = SettingsJsonPath();
+
+        // Add settings here when needed
+        // Settings.Add(setting);
+
+        // Load settings from file upon initialization
+        LoadSettings();
+
+        Settings.SettingsChanged += (s, a) => this.SaveSettings();
+    }
+}

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/Pages/RegistryListPage.cs

@@ -18,12 +18,14 @@ internal sealed partial class RegistryListPage : DynamicListPage
     public static IconInfo RegistryIcon { get; } = new("\uE74C"); // OEM
 
     private readonly CommandItem _emptyMessage;
+    private readonly ISettingsInterface _settingsManager;
 
-    public RegistryListPage()
+    public RegistryListPage(ISettingsInterface settingsManager)
     {
         Icon = Icons.RegistryIcon;
         Name = Title = Resources.Registry_Page_Title;
         Id = "com.microsoft.cmdpal.registry";
+        _settingsManager = settingsManager;
         _emptyMessage = new CommandItem()
         {
             Icon = Icons.RegistryIcon,

src/modules/cmdpal/ext/Microsoft.CmdPal.Ext.Registry/RegistryCommandsProvider.cs

@@ -2,6 +2,7 @@
 // The Microsoft Corporation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
+using Microsoft.CmdPal.Ext.Registry.Helpers;
 using Microsoft.CmdPal.Ext.Registry.Properties;
 using Microsoft.CommandPalette.Extensions;
 using Microsoft.CommandPalette.Extensions.Toolkit;
@@ -10,6 +11,8 @@ namespace Microsoft.CmdPal.Ext.Registry;
 
 public partial class RegistryCommandsProvider : CommandProvider
 {
+    private static readonly ISettingsInterface _settingsManager = new SettingsManager();
+
     public RegistryCommandsProvider()
     {
         Id = "Windows.Registry";
@@ -20,7 +23,7 @@ public partial class RegistryCommandsProvider : CommandProvider
     public override ICommandItem[] TopLevelCommands()
     {
         return [
-            new CommandItem(new RegistryListPage())
+            new CommandItem(new RegistryListPage(_settingsManager))
             {
                 Title = "Registry",
                 Subtitle = "Navigate the Windows registry",