macOS: Use tool environment to ensure tests load matching Qt libraries
Linking with a framework suffix to pick up the debug version of
libraries doesn't work as long as the dependencies picked up from prl
files are not rewritten to also include the suffix. The result is that
we end up loading both release and debug versions of the Qt libraries.
Use the target environment (target_wrapper.sh) to set the image suffix
instead, which means 'make check' will automatically work.
Reviewed-by: Timur Pocheptsov <email@example.com>
Reviewed-by: Tor Arne Vestbø <firstname.lastname@example.org>