Move login flow management to AppCoordinator

[SBiOSoftWhare]

TODO:

• First implement Move Matrix sessions management in a dedicated class #3618
• Move login management from -[MasterTabBarController viewDidAppear] to AppCoordinator.start()
• In AppCoordinator.start() try do not show SplitViewCoordinator until login succeed. If possible try to animate transition from authentication to split view (including tab bar)