0032723: Draw Harness, ViewerTest - sloppy animation in WebGL

0032723: Draw Harness, ViewerTest - sloppy animation in WebGL

Fixed emscripten_async_call() calls to use requestAnimationFrame() instead of setTimeout().
ViewerTest_EventManager::handleViewRedraw() - fixed queuing new onWasmRedrawView()
before previous one has been processed (leading to multiplying of pending redraws executed at the same time).
RWGltf_TriangulationReader::readDracoBuffer - suppressed CLang compilation warnings.