Improve performance of memory transfer

Use a different queue family specifically for transfer operations. It will require you to make the following modifications to your program:

- Modify QueueFamilyIndices and findQueueFamilies to explicitly look for a queue family with the VK_QUEUE_TRANSFER bit, but not the VK_QUEUE_GRAPHICS_BIT.

- Modify createLogicalDevice to request a handle to the transfer queue

- Create a second command pool for command buffers that are submitted on the transfer queue family

- Change the sharingMode of resources to be VK_SHARING_MODE_CONCURRENT and specify both the graphics and transfer queue families

- Submit any transfer commands like vkCmdCopyBuffer (which we'll be using in this chapter) to the transfer queue instead of the graphics queue