As a first step towards replacing the Reanimated 1 syntax in LoggedOutModal with Reanimated 2 syntax (ENG-8146), I'm converting the class component to a function component.

This diff makes minimal changes. In a later diff I'll make some improvements to memoization now that we're using a function component and can use React.useMemo and friends.

Depends on D12190

I tested this diff stack by playing around with LoggedOutModal on my iOS simulator in my local environment:

1. I navigated to LogInPanel and back
2. I navigated to LegacyRegisterPanel and back
3. I navigated to FullscreenSIWEPanel and back
4. I navigated to QRCodeSignInNavigator and back
5. I navigated to Registration and back