Io abstraction (#7293)

Co-authored-by: p-storm <paul.de.man@gmail.com>

src/modules/previewpane/common/PreviewHandlerCommon.csproj

@@ -148,6 +148,9 @@
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
+    <PackageReference Include="System.IO.Abstractions">
+      <Version>12.2.5</Version>
+    </PackageReference>
   </ItemGroup>
   <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />

src/modules/previewpane/common/Utilities/ReadonlyStream.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.Diagnostics;
 using System.IO;
 using System.Runtime.InteropServices;
 using System.Runtime.InteropServices.ComTypes;

src/modules/previewpane/common/examplehandler/CustomControlTest.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System;
-using System.IO;
 using System.Windows.Forms;
 
 namespace Common