[Peek]Peek and Monaco file encoding issues are solved with a encoding detector (#26955)

* [Peek] Peek and Monaco file encoding issues are solved with a encoding detector.

* [Peek] Monaco encoding parameter is moved to another function.

* [Peek] NOTICE.md update.

* [Peek] Spell Check update.

* UTF-Unknown is added to Nuget list in Notice.md

* System.Text.Encoding.CodePages is added to Nuget list in Notice.md

* [Peek] Unncessary mainfest files are deleted.

* [Peek ] Unncessary mainfest file are deleted.

* [Peek] Encoding null check is added.

* Update NOTICE.md

* Update NOTICE.md

* ci: Add signing to UtfUnknown

src/common/FilePreviewCommon/FilePreviewCommon.csproj

@@ -14,6 +14,8 @@
 
   <ItemGroup>
     <PackageReference Include="Markdig.Signed" />
+    <PackageReference Include="System.Text.Encoding.CodePages" />
+    <PackageReference Include="UTF.Unknown" />
   </ItemGroup>
 
   <ItemGroup>

src/common/FilePreviewCommon/MonacoHelper.cs

@@ -107,6 +107,7 @@ namespace Microsoft.PowerToys.FilePreviewCommon
         public static string ReadIndexHtml()
         {
             string html;
+
             using (StreamReader htmlFileReader = new StreamReader(new FileStream(MonacoDirectory + "\\index.html", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)))
             {
                 html = htmlFileReader.ReadToEnd();