dotnet list package should warn when restore is not current

[zivkan]

NuGet Product(s) Involved

dotnet.exe

The Elevator Pitch

dotnet list package gets "actual" package usage from NuGet's assets file, which is created on restore. Which means that if a customer restores a project, then edits the project to change a package version, or add/remove a package reference, then runs dotnet list package without restoring, it will show incorrect information, and the customer will not know why.

dotnet list package should show a message when the project restore isn't up-to-date

Additional Context and Details

dotnet list package already loads the project file via MSBuild APIs (hence why it only works with SDK style projects that the dotnet CLI can build/evaluate), meaning we already have the data to do a restore no-op check.

[jebriede]

Adjusting priority after discussion with @zivkan