Add metadata to restore tests, make them go through the no-op codepath

[nkolev92]

While I investigating #10068, I hit an known problem of the no-op codepath not being exercised in a good amount of unit test.

The reason is that the packagespec is not created with the same amount of details prod package spec would be.
In prod scenarios, all restores go through the restorerunner which calls https://github.com/NuGet/NuGet.Client/blob/c3219e49852add8371db25680a300cce5551ef00/src/NuGet.Core/NuGet.Commands/RestoreCommand/Utility/SpecValidationUtility.cs#L28 to validate that things like the RestoreMedata are not null or empty.

Now this is not a major problem for no-op, I have not discovered any regressions because of this, but it does not reflect what the actual restore code run is.