Improved UX for nuget developers - referencing project as nuget

### Summary

V-Next continutation of https://github.com/dotnet/msbuild/issues/8398
Add option to to treat referenced project (`ProjectReference`) as NuGet package (`PackageReference`).

This way the package developer could have a solution containing the project producing the package as well as project integration testing the package, that is utilizing not only the actual code, but as well other possible assets (analyzers, msbuild .props/.targets files). This can currently be achieved only via additional steps (packing the project, flushing nuget caches, adding the location with build package to sources, referencing the build package).

Related:
* https://github.com/NuGet/Home/issues/6579
* https://github.com/dotnet/sdk/issues/1151
* https://stackoverflow.com/questions/42773815/net-core-csproj-global-json-projects-equivalent