Implement render info counters for the 2D renderer

This provides information for the debug monitors

servers/rendering_server.h

@@ -961,6 +961,7 @@ public:
 	enum ViewportRenderInfoType {
 		VIEWPORT_RENDER_INFO_TYPE_VISIBLE,
 		VIEWPORT_RENDER_INFO_TYPE_SHADOW,
+		VIEWPORT_RENDER_INFO_TYPE_CANVAS,
 		VIEWPORT_RENDER_INFO_TYPE_MAX
 	};