[cmdpal] Migrate some plugin's unit tests from PT run to cmdpal. (#40462)

<!-- 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
Migrate blow plugin's from UT to cmdpal:
1. TimeDate
2. WindowWalker
3. System
4. Registry

This PR is mostly helped by Copilot. Please feel free to change cases in
the future.

<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

- [x] **Closes:** #40461
- [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

<!-- 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

---------

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

src/modules/cmdpal/Tests/Microsoft.CmdPal.Ext.System.UnitTests/QueryTests.cs

@@ -0,0 +1,105 @@
+// 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.Linq;
+using Microsoft.CmdPal.Ext.System.Helpers;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace Microsoft.CmdPal.Ext.System.UnitTests;
+
+[TestClass]
+public class QueryTests
+{
+    [DataTestMethod]
+    [DataRow("shutdown", "Shutdown")]
+    [DataRow("restart", "Restart")]
+    [DataRow("sign out", "Sign out")]
+    [DataRow("lock", "Lock")]
+    [DataRow("sleep", "Sleep")]
+    [DataRow("hibernate", "Hibernate")]
+    public void SystemCommandsTest(string typedString, string expectedCommand)
+    {
+        // Setup
+        var commands = Commands.GetSystemCommands(false, false, false, false);
+
+        // Act
+        var result = commands.Where(c => c.Title.Contains(expectedCommand, StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
+
+        // Assert
+        Assert.IsNotNull(result);
+        Assert.IsTrue(result.Title.Contains(expectedCommand, StringComparison.OrdinalIgnoreCase));
+    }
+
+    [TestMethod]
+    public void RecycleBinCommandTest()
+    {
+        // Setup
+        var commands = Commands.GetSystemCommands(false, false, false, false);
+
+        // Act
+        var result = commands.Where(c => c.Title.Contains("Recycle", StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
+
+        // Assert
+        Assert.IsNotNull(result);
+    }
+
+    [TestMethod]
+    public void NetworkCommandsTest()
+    {
+        // Test that network commands can be retrieved
+        try
+        {
+            var networkPropertiesList = NetworkConnectionProperties.GetList();
+            Assert.IsTrue(networkPropertiesList.Count >= 0); // Should not throw exceptions
+        }
+        catch (Exception ex)
+        {
+            Assert.Fail($"Network commands should not throw exceptions: {ex.Message}");
+        }
+    }
+
+    [TestMethod]
+    public void UefiCommandIsAvailableTest()
+    {
+        // Setup
+        var firmwareType = Win32Helpers.GetSystemFirmwareType();
+        var isUefiMode = firmwareType == FirmwareType.Uefi;
+
+        // Act
+        var commands = Commands.GetSystemCommands(isUefiMode, false, false, false);
+        var uefiCommand = commands.Where(c => c.Title.Contains("UEFI", StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
+
+        // Assert
+        if (isUefiMode)
+        {
+            Assert.IsNotNull(uefiCommand);
+        }
+        else
+        {
+            // UEFI command may still exist but be disabled on non-UEFI systems
+            Assert.IsTrue(true); // Test environment independent
+        }
+    }
+
+    [TestMethod]
+    public void FirmwareTypeTest()
+    {
+        // Test that GetSystemFirmwareType returns a valid enum value
+        var firmwareType = Win32Helpers.GetSystemFirmwareType();
+        Assert.IsTrue(Enum.IsDefined(typeof(FirmwareType), firmwareType));
+    }
+
+    [TestMethod]
+    public void EmptyRecycleBinCommandTest()
+    {
+        // Test that empty recycle bin command exists
+        var commands = Commands.GetSystemCommands(false, false, false, false);
+        var result = commands.Where(c => c.Title.Contains("Empty", StringComparison.OrdinalIgnoreCase) &&
+                                         c.Title.Contains("Recycle", StringComparison.OrdinalIgnoreCase)).FirstOrDefault();
+
+        // Empty recycle bin command should exist
+        Assert.IsNotNull(result);
+    }
+}