vkconfig: Add Vulkan SDK installation management

[christophe-lunarg]

https://vulkan.lunarg.com/content/view/latest-sdk-version-api

[richard-lunarg]

I got a request recently for customizing the path of the VulkanSDK, and "remembering" the custom path, and automatically removing the old SDK. This may not be a job for vkconfig, but it could certainly be handled by it. The current SDK, names the install folder with the version. This is a result of someone assuming developers would want multiple SDK's installed. I don't think this is really largely the case. Just installing in /VulkanSDK, using the same path for each one, and allowing the installer (or vkconfig) to remove the last SDK would make a lot more sense. The SDK can be removed pretty easily (on Windows/macOS) by running the maintenancetool.exe (or .app) in the SDK folder. It will take command line parameters that would remove the entire SDK, and this could be run before installing the new SDK.

[christophe-lunarg]

On Linux, vkconfig can be installed using a package, in that case we can't uninstall.