Vulkan doesn't have a memory allocator builtin. The application should
provide the memory allocator at runtime. Vulkan Memory Allocator is a
widely used implementation.
Vulkan Memory Allocator is a header only implementation, but the using
application should compile a part in a CPP compile unit. The file
`vk_mem_alloc_impl.cc` and `extern_vulkan_memory_allocator` library
is therefore introduced.
Reviewed By: fclem
Differential Revision: https://developer.blender.org/D16572
