[UITest] Added UITest for advancedPaste (#40745)

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## Summary of the Pull Request
Added UITest for advancedPaste
Also add test init code for color picker and settings.
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## PR Checklist

- [ ] **Closes:** #xxx
- [ ] **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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## Detailed Description of the Pull Request / Additional comments

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## Validation Steps Performed

---------

Signed-off-by: Shawn Yuan <shuaiyuan@microsoft.com>

src/modules/AdvancedPaste/UITest-AdvancedPaste/Helper/FileReader.cs

@@ -0,0 +1,85 @@
+// 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.IO;
+using System.Text;
+using System.Windows.Forms;
+
+namespace Microsoft.AdvancedPaste.UITests.Helper;
+
+public class FileReader
+{
+    public static string ReadContent(string filePath)
+    {
+        try
+        {
+            return File.ReadAllText(filePath);
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException($"Failed to read file: {ex.Message}", ex);
+        }
+    }
+
+    public static string ReadRTFPlainText(string filePath)
+    {
+        try
+        {
+            using (var rtb = new System.Windows.Forms.RichTextBox())
+            {
+                rtb.Rtf = File.ReadAllText(filePath);
+                return rtb.Text;
+            }
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException($"Failed to read plain text from file: {ex.Message}", ex);
+        }
+    }
+
+    /// <summary>
+    /// Compares the contents of two RTF files to check if they are consistent.
+    /// </summary>
+    /// <param name="firstFilePath">Path to the first RTF file</param>
+    /// <param name="secondFilePath">Path to the second RTF file</param>
+    /// <param name="compareFormatting">If true, compares the raw RTF content (including formatting).
+    /// If false, compares only the plain text content.</param>
+    /// <returns>
+    /// A tuple containing: (bool isConsistent, string firstContent, string secondContent)
+    /// - isConsistent: true if the files are consistent according to the comparison method
+    /// - firstContent: the content of the first file
+    /// - secondContent: the content of the second file
+    /// </returns>
+    public static (bool IsConsistent, string FirstContent, string SecondContent) CompareRtfFiles(
+        string firstFilePath,
+        string secondFilePath,
+        bool compareFormatting = false)
+    {
+        try
+        {
+            string firstContent, secondContent;
+
+            if (compareFormatting)
+            {
+                // Compare raw RTF content (including formatting)
+                firstContent = ReadContent(firstFilePath);
+                secondContent = ReadContent(secondFilePath);
+            }
+            else
+            {
+                // Compare only the plain text content
+                firstContent = ReadRTFPlainText(firstFilePath);
+                secondContent = ReadRTFPlainText(secondFilePath);
+            }
+
+            bool isConsistent = string.Equals(firstContent, secondContent, StringComparison.Ordinal);
+            return (isConsistent, firstContent, secondContent);
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException($"Failed to compare RTF files: {ex.Message}", ex);
+        }
+    }
+}