Add support for dot indicator to BottomTabs.

This approach is still not ideal as it assumes there's a visible stack somewhere in the Hierarchy.
It's better than the current implementation so I'm pushing it and will reiterate in the future if needed.

* Fix top bar layout frame, Closes #5003

* Set layout child view controllers on initialization

* Remove duplicate initWithLayoutInfo: function

* Stop manually manage viewControllers store, Iterate layout instead

* Update RNNCommandsHandlerTest.m

* Explicitly attach and detach viewControllers in store
* Stop registering components in commands handler