Renderer: Handle resize events on-demand instead of polling

We now differentiate between a resize event and surface change/destroyed
event, reducing the overhead for resizes in the Vulkan backend. It is
also now now safe to change the surface multiple times if the video thread
is lagging behind.

Source/Core/VideoBackends/OGL/Render.h

@@ -121,8 +121,6 @@ public:
 
   void ReinterpretPixelData(unsigned int convtype) override;
 
-  void ChangeSurface(void* new_surface_handle) override;
-
 private:
   void UpdateEFBCache(EFBAccessType type, u32 cacheRectIdx, const EFBRectangle& efbPixelRc,
                       const TargetRectangle& targetPixelRc, const void* data);
@@ -133,6 +131,9 @@ private:
   void BlitScreen(TargetRectangle src, TargetRectangle dst, GLuint src_texture, int src_width,
                   int src_height);
 
+  void CheckForSurfaceChange();
+  void CheckForSurfaceResize();
+
   std::array<const AbstractTexture*, 8> m_bound_textures{};
 };
 }