Add minimal set of tests to build for static Qt configs in Coin

With qmake (afaik) we never built tests and examples for static Qt configs (iOS, WebAssembly, any host platform).
One of the main reasons is the blow up in artifact size due to linking Qt to each of the test and examples.

With the new CI yaml instructions and CMake, what we could do is add a feature that enables the building of a very small subset of examples and tests, and then add such configs to the CI.

This would ensure the artifact size does not explode, and allow us to catch build regressions for configs that we never tested before.

We could also keep it limited to qtbase first.