Merge changes Ieb55dfec,I08e5647f,I446192e3,I9e2d9af6

* changes:
  vkjson: refactor based on 1.1 assumptions
  libvulkan: fix support for promoted VK_KHR_external_* extensions
  libvulkan: fix support for promoted GPDP2
  libvulkan: fix support for 1.1 vkEnumeratePhysicalDeviceGroups