Project template is missing minimal UI tests #160
Description
Background
The ProjectTemplate project is used to create new lab experiments, and is an "MVP" in a way. If this project works, all new projects should work as a clean slate.
The problem
We've added UI tests and test-focused source generators (#156) to labs, but we haven't added any examples demonstrating basic usage. If we had these, we could also use them to test that absolute minimum test functionality is working as intended, even as projects come and go.
The solution
The best place for this is the ProjectTemplate project. The tests for this project are already run as part of the CI, and these tests are the first that a user will see when they start writing tests.