Provide way to launch wayland client application

Running both QtWayland compositor and client application from QtCreator to a Boot2Qt target device is currently not possible. When client application is started, appcontroller will always terminate any other application already running in the device (that was also launched by appcontroller).

There should be way to let appcontroller know that current application should be launched without terminating previous application. This is already supported in appcontroller with "–launch" parameter, just needs to have something in the QtCreator side to enable it.