Add v4 template project

[Barsonax]

Summary

From #820:

• Move the DualityProjectTemplate that we'll bundle in the download .zip to somewhere inside this repo.

  • Consider adding an automated .zip pack step in some .csproj, like it was done for the now obsolete embedded GamePluginTemplate, so it doesn't need to be zipped manually for release.
  • Remove the now obsolete "package .zip" build step from NightlyBuilder.

Best is to add a new project that contains the new template and is responsible for packing/deploying it: https://github.com/Barsonax/DualityProjectTemplate