renderer_vulkan: Add setting to log pipeline statistics

Use VK_KHR_pipeline_executable_properties when enabled and available to
log statistics about the pipeline cache in a game.

For example, this is on Turing GPUs when generating a pipeline cache
from Super Smash Bros. Ultimate:

Average pipeline statistics
==========================================
Code size:       6433.167
Register count:    32.939

More advanced results could be presented, at the moment it's just an
average of all 3D and compute pipelines.

src/common/settings.h

@@ -314,6 +314,7 @@ struct Values {
     // Renderer
     Setting<RendererBackend> renderer_backend{RendererBackend::OpenGL, "backend"};
     BasicSetting<bool> renderer_debug{false, "debug"};
+    BasicSetting<bool> renderer_shader_feedback{false, "shader_feedback"};
     BasicSetting<bool> enable_nsight_aftermath{false, "nsight_aftermath"};
     BasicSetting<bool> disable_shader_loop_safety_checks{false,
                                                          "disable_shader_loop_safety_checks"};