Use the graphics queue by default for Image::generateMipmaps and Image::blitTo...
vkCmdBlitImage is only supported by graphics queues. See here: https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/vkCmdBlitImage.html
vkCmdBlitImage is only supported by graphics queues. See here: https://www.khronos.org/registry/vulkan/specs/1.1-extensions/man/html/vkCmdBlitImage.html