vulkaninfo: Print human-readable heap sizes
vulkaninfo: Print human-readable heap sizes

Since the size of a memory heap can be rather substantial, it is helpful
to have the size additionally printed out in a human-readable format,
i.e. using prefixes.

Change-Id: I47aad4fce06471804ce9e853ba300626b6ad34c8

KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools,KhronosGroup/Vulkan-Tools