React to deprecation of Microsoft.AspNetCore.App.
Changes:
* Update KnownFrameworkReference to use the new runtime packs
* Stop reference Microsoft.AspNetCore.App
* Stop generating unused variable in the SDK: BundledAspNetCoreAppPackageVersion and BundledAspNetCoreAppTargetFrameworkVersion
* Add prodcon entries for all aspnet dependencies. These may not have the same version in the future (like patch updates)