Ensure Test Adapter Dependency DLLs are Copied to VSIX (#1257)

**Problem**
Test adapter depends on newtonsoft.json and Microsoft.VisualStudio.Shell.Interop. These are not included on their own in our vsix.

My previous fix just updated the vsix manifest and did not properly include these files

**Fix**
Add copy  step to ensure we copy these files to the vsix.

Author: mjbvz

Nodejs/Product/Nodejs/Nodejs.csproj

@@ -730,6 +730,16 @@
       <IncludeInVSIX>true</IncludeInVSIX>
       <VSIXSubPath>.</VSIXSubPath>
     </Content>
+    <Content Include="$(OutputPath)\Newtonsoft.Json.dll">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <IncludeInVSIX>true</IncludeInVSIX>
+      <VSIXSubPath>.</VSIXSubPath>
+    </Content>
+    <Content Include="$(OutputPath)\Microsoft.VisualStudio.Shell.Interop.dll">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+      <IncludeInVSIX>true</IncludeInVSIX>
+      <VSIXSubPath>.</VSIXSubPath>
+    </Content>
     <Content Include="Credits.txt">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
       <IncludeInVSIX>true</IncludeInVSIX>

Nodejs/Product/Nodejs/source.extension.vsixmanifest

@@ -29,6 +29,6 @@
     <Asset Type="Microsoft.VisualStudio.ProjectTemplate" d:Source="Project" d:ProjectName="%CurrentProject%" d:TargetPath="|%CurrentProject%;TemplateProjectOutputGroup|" Path="ProjectTemplates" d:VsixSubPath="ProjectTemplates" />
     <Asset Type="Microsoft.VisualStudio.ItemTemplate" d:Source="Project" d:ProjectName="%CurrentProject%" d:TargetPath="|%CurrentProject%;TemplateProjectOutputGroup|" Path="ItemTemplates" d:VsixSubPath="ItemTemplates" />
     <Asset Type="Microsoft.VisualStudio.Assembly" d:Source="File" Path="Newtonsoft.Json.dll" AssemblyName="Newtonsoft.Json, Version=6.0.0.0, Culture=neutral, PublicKeyToken=30ad4fe6b2a6aeed" />
-	<Asset Type="Microsoft.VisualStudio.Assembly" d:Source="File" Path="Microsoft.VisualStudio.Shell.Interop.dll" AssemblyName="Microsoft.VisualStudio.Shell.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
+  	<Asset Type="Microsoft.VisualStudio.Assembly" d:Source="File" Path="Microsoft.VisualStudio.Shell.Interop.dll" AssemblyName="Microsoft.VisualStudio.Shell.Interop, Version=7.1.40304.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
   </Assets>
 </PackageManifest>