Warn about unsuitable CMake versions in user projects like we do during Qt build

When doing a Qt build, if an unsuitable CMake version is detected, we issue a warning.

We might want to consider issuing some of these warnings when a Qt package is used in user project.
Only some, because not all might be relevant for user projects.
An example would be any AUTOGEN related issue in upstream CMake.

We'd also want to provide an opt-out, in case users can't update the CMake version they are using.