Determine when the app should enter the Loaded state

Currently, the app enters "Loaded" at some point after the wasm module has been dowloaded and compiled, but before the app draws the first frame. This causes the app to display a blank screen after the splash screen has been removed.

This is most easily reproducible with debug builds, but can happen for any app which has non-instant startup time.

Investigate if it's feasible to delay entering the loaded state to after the first frame has been painted.