Suggest reloading preview when scene breaks

A lot of times, while doing hot reloading, the reload doesn't work and it breaks the loading of the scene. Sometimes this can be fixed by forcing another hot-reload, or writing /reload on the chat.

A lot of times it's frustrating to not know if the scene is taking time to load, if the last change I did broke something, or if it's a hot reload issue.

If there's a way to identify when the scene's loading has broken, we should display something visible in the screen. Ideally including a button that can be clicked to reload.