tests/functional: Convert the virtio_gpu avocado test into a standalone test

Nothing thrilling in here, it's just a straight forward conversion.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20240830133841.142644-25-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2 files changed