When passing a package source as part of a `dotnet add package` in
our acceptance testing framework, dotnet was then trying to use that
package source for the restoration of other packages in the csproj
file.
We have removed passing the source to dotnet add package add
and replaced it with adding a machine level package source via
dotnet nuget add source command
this is the more correct way to work and will allow us to be able
to search multiple locations as part of the dotnet restore command
Just what it says on the tin.
The SDK code generator will be updated to use the new `urn`
resource option inside of each module's implementation of
`ResourceModule.construct`.
Part of #2430.
Co-authored-by: Justin Van Patten <jvp@justinvp.com>