Add a cmake test that builds a simple widgets application, installs
it, in a shared Qt build deploys the runtime dependencies and then
runs it to confirm that the app works.
With a static Qt, the installation of the runtime dependencies is
skipped, but the app should still run.
The test is expected to pass only when targeting Windows and macOS
(both when using shared and static Qt).
Pick-to: 6.3
Task-number: QTBUG-98545
Change-Id: I41b616e1e1fc463d57c64be9273ed4dc755e9187
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
