vk_graphics_pipeline: Initial implementation

This abstractio represents the state of the 3D engine at a given draw.
Instead of changing individual bits of the pipeline how it's done in
APIs like D3D11, OpenGL and NVN; on Vulkan we are forced to put
everything together into a single, immutable object.

It takes advantage of the few dynamic states Vulkan offers.

src/video_core/CMakeLists.txt

@@ -161,6 +161,8 @@ if (ENABLE_VULKAN)
         renderer_vulkan/vk_descriptor_pool.h
         renderer_vulkan/vk_device.cpp
         renderer_vulkan/vk_device.h
+        renderer_vulkan/vk_graphics_pipeline.cpp
+        renderer_vulkan/vk_graphics_pipeline.h
         renderer_vulkan/vk_image.cpp
         renderer_vulkan/vk_image.h
         renderer_vulkan/vk_memory_manager.cpp