Add integration test for Frosting template

It would be nice to have integration tests for Frosting template on different platforms. Test should install the Frosting template from the build artifacts, create a new Frosting project and run it.

Start by locating the integration-test and build-artifact workflows in the Cake repository, then identify how the Frosting template is packaged. Run the existing build and test entry points to understand how artifacts are produced; done means installing the template from those artifacts on the supported platforms, creating a Frosting project, and running it successfully.

Written by the indexing model from the issue text.