macOS: Bundle apps from cpack instead of cmake

[mizvekov]

When distributing VulkanTools through a MacOS package manager, such as homebrew for example, we don't want them bundled in a MacOS App.

So the process for building these on MacOS is basically the same as for linux or other unix distribution.

For example, on vkconfig/CmakeLists.txt, we would wish to just take the NOT APPLE path.

Instead of handling this through CMakeLists.txt and inventing a new cmake configuration variable, we can instead deploy an app through an appropriate cpack configuration. So you can use that for VulkanSDK, but package based distros would not use cpack and just go through the normal install route.