Implicit state overlay not appearing on package dependency nodes

[drewnoakes]

Before the dependencies tree rewrite in #9008, PackageReference MSBuild items defined outside of the current project's .csproj file would be displayed with a padlock overlay, indicating it's an implicit reference, which may not be removed from the project. Those overlays are no longer visible.

To repro this, create a project and add one package reference to it, and add a Directory.Build.props file with a different package reference in it.

In this example, Figgle is added in Directory.Build.props and should show as implicit.

We can see this state works for framework and analyzer nodes:

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Beyond the lack of visual indicator, we use the implicit state to prevent attempts at deletion by hiding the "Remove" context menu command. In the above screenshot if you attempt to remove the "Figgle" package, you see this error: