feat(App): refactor App and split it into BaseApp and App
BaseApp does all the heavy-lifting related to creating the redux store,
navigation, and so on.
App currently handles URL props and actually triggering navigation based on
them.
Contributing all buttons in one place goes against the designs that we
set out at the beginning of the project's rewrite and that multiple of
us have been following since then.
[Android] Fix possible TypeError in multi-JitsiMeetView SDK consumers
If multiple JitsiMeetView instances are created (not necessarily
existing at once), it's possible to hit a TypeError when reading the
React Component props of the currently mounted App. Anyway, in certain
places we're already protecting against that out of abundance of caution
so it makes no sense to not protect everywhere.