message: Add MahApp.Metro reference
diff: </PropertyGroup>
  <ItemGroup>
  + <PackageReference Include="MahApps.Metro" Version="2.4.1" />
  <PackageReference Include="Microsoft.AnalysisServices.NetCore.retail.amd64" Version="19.12.3-Preview" />
  <PackageReference Include="Microsoft.Extensions.Hosting" Version="5.0.0-rc.2.20475.5" />
  <PackageReference Include="Microsoft.Extensions.Http" Version="5.0.0-rc.2.20475.5" />
  