vk renderer update

[wsqjny]

Hi~ I'm new to vulkan. very happy to see your pbr demo source, it helps me a lot. However, I found in the new version of vulkan (1.2.154.1), the following two places seem to need to be changed:

1. Validation Layers changed : VK_LAYER_LUNARG_standard_validation -> VK_LAYER_KHRONOS_validation. https://vulkan.lunarg.com/doc/view/1.1.114.0/windows/validation_layers.html

2. There are some image layout warnings when running, like ".....(subresource: aspectMask 0x1 array layer 0, mip level 1) to be in layout VK_IMAGE_LAYOUT_GENERAL--instead, current layout is VK_IMAGE_LAYOUT_UNDEFINED." It seems that all the mips of the "envTextureUnfiltered" image shouled be changed before cs dispatch.

Thank you~