title: get mesh/face/vertices count in BabylonJS outside of the inspector
body: <p>I would like to be able to show some basic stats for my scene in BabylonJS, without needing to display the <a href="https://doc.babylonjs.com/toolsAndResources/tools/performanceProfiler" rel="nofollow noreferrer">inspector</a>. Is there a way to get those statistics from the scene?</p>