New Splash Screen

closes #1768 (closed)

Note: splash screen is handled in native ground while the app inits, but we don't know wich theme is selected until the app has already launched, so we can't switch between light and dark theme in the splash.

So, what we are doing here is always use dark splash, because the impact for a user that is using light theme and sees the dark splash is less than that of the user that is using dark theme and sees the light splash.