Changes: * IsProductPackage => IsShippingPackage * artifacts/$config/packages => artifacts/packages/$config * packages/product => packages/Shipping * packages/internal => packages/NonShipping * Renamed MSBuild properties used for output folders * Update build tools to use 2 spaces in global.json
Part of #4246 Changes: * Update source code layout to follow the new conventions for this repo * Update project files to use `<Reference>` * Update targets to build NPM packages * Update BuildTools to support custom 'restore' and 'test' targets