This uses a feature of KoreBuild which will select PackageReference
versions based on a lineup file. This helps unify versions between repos
and helps us ensure we are consistent across multiple components.
- Added 1_X src project for multitargeting
- Added 1_X test project for multitargeting
- Added 1_X test MvcShim for multitargeting
- Make section directive generate the correct code the appropriate version
- Added another sln