Proj0809: Global package references are meant for private assets only

When using Central Package Management, in the central Directory.Packages.props it is possible to define package references globally with the use of <GlobalPackageReference>. This should only be used for references that should be handled as a private asset.

Non-compliant

<Project>

  <PropertyGroup>
    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
  </PropertyGroup>

  <ItemGroup>
    <GlobalPackageReference Include="Qowaiv" Version="7.0.0" />
  </ItemGroup>

</Project>

Compliant

<Project>

  <PropertyGroup>
    <ManagePackageVersionsCentrally>true</ManagePackageVersionsCentrally>
  </PropertyGroup>

  <ItemGroup>
    <GlobalPackageReference Include="DotNetProjectFile.Analyzers" Version="1.5.8" />
  </ItemGroup>

</Project>