Lots of todos, this should probably just be its own self-contained
object to allow the emulator to render "headlessly" regardless of a
swapchain existing or not.
This value is needed for vulkan to properly allocate a surface, and would benefit OpenGL to move more of its initialization code into here rather than in `emulator.cpp`.
Headlessly creates a new vulkan instance, with conditional MacOS
support, and enables the `VK_EXT_debug_utils` instance-extension with a
debug-messenger to hook onto validation layer messages.
A lot of the architecture of the emulator here does not allow for vulkan
to initialize easily since it involves a bit of data to be exchanged
between SDL and Vulkan. This commit just adds the foundational linkage
and library code for vulkan support.
