yuzu-qt: Attempt to workaround broken Vulkan installations

This does a few things in order to make the default setting Vulkan
workable.

- When yuzu boots, it just opens the Vulkan library.
  - If it works, all good and we continue with Vulkan as the default.
  - If something breaks, a new file in the config directory will be left
    behind (this is deleted normally).
- If Vulkan is not working, has_broken_vulkan is set to true.
  - The first time this happens, a warning is displayed to notify the
    user.
  - This forces use of OpenGL, and Vulkan cannot be selected.
  - The Shader Backend selector is made accessible for use in custom
    configurations.
  - To disable has_broken_vulkan, the user needs to press a button in
    Graphics Configuration to manually run the Vulkan device
    enumeration.