There is a race condition in the root navigatior's initialization.
It's possible that it's initialized a touch too late and SDK users who
try to navigate to a conference end up stuck in the connecting screen
because the navigator is null.
This PR waits for it to be initilized by very unorthodox means, it's a
horrible hack which we need to undo, but for that we need to break
appart the inheritance relationship between App.{web,native},
AbstractApp and BaseApp because it's very inflexible.
The flags are now initialized very early so the naviggator sees if the
welcome page is enabled or not.
Only havee the screen in the hierarchy if we have a welcome page, since
it's the only way to access it.
Use goBack() from the navigator directly and avoid duplicating all props
to the screen.
Converted LoadConfigOverlay to a JitsiScreen component that right now is part of navigation as ConnectingPage, plus I
separated appNative and other actions into web and native.
Calin Chitu
Saúl Ibarra Corretgé
Hristo Terezov
Calinteodor