For the external api to fire update events out of the iframe, it
must first be initialized within the jitsi app. Any invocations
by the app to send updates events before initialization will
cause the api to swallow the events. The chosen fix is to
initialize the api earlier so the first update of app's redux
store fires update events that the api will also fire out of
the iframe.

This change will affect current behavior in that right now
the update event of the initial set of the avatar url is
blocked, but the change will make that event fire out of the
iframe.

* Prints errors in case of wrong initialization.

Not printing can masks some errors in the code.

* Allow only one Follow Me moderator in a meeting.

* Sends Follow Me state with all presences of the moderator.

This fixes an issue where the moderator sends the Follow Me state and then for example mute or unmute video (this will produce a presence without Follow Me state) and the new comers will not reflect current Follow Me state till a change of it comes.

* Changes fixing comments.

* Changes fixing comments.

🔥🔥🔥

Using anything non-serializable for action types is discouraged:
https://redux.js.org/faq/actions#actions

In fact, this is the Flow definition for dispatching actions:

declare export type DispatchAPI<A> = (action: A) => A;
declare export type Dispatch<A: { type: $Subtype<string> }> = DispatchAPI<A>;

Note how the `type` field is defined as a subtype of string, which Symbol isn’t.

componentWillMount is a deprecated lifecycle method;
componentDidMount should be used to kick off things
like ajax. In the case of the _App hierarchy, a promise
chain is used to perform initialization, and it is
first started in the constructor by initializing
storage. However, by the time storage is initialized,
resolving the first promise, _App has already mounted.
So, move it all to the componentDidMount lifecycle.

There doesn't seem to be a strong need for the initialized React
Component state in BaseApp so remove/delete it.

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.