Allow setting UITabBarItem.title to default value (#5280)
The default value for `UITabBarItem.title` is `nil` as specified by the docs:
> You should set this property before adding the item to a bar. The default value is nil.
https://developer.apple.com/documentation/uikit/uibaritem/1616412-title
This changes allows for this to be `nil`.
* bind viewController to presenters using bindViewController
* Merge options to the specific provided layout
* Moved custom titleView creation to RNNRootViewController
* Moved default options to presenters, moved options applying to presenters, resolved options in RNNOptionsResolver
* Fixes merge options
* Fixes topBar transition on pop
* Prevent titleView creation when react titleView exists
* Fixed unit tests
* Options refactor WIP
* Detach applied options from DTO - WIP
* Added option types and option parsers
* Unit test passes
* Added presenters for each parent type
* Fixes unit tests
* Rename StringParam to Text, changed bottomTabs.drawBehind and topBar.drawBehind default to false
* set layout.backgroundColor default to white
* Added unit tests for RNNViewControllerPresenter
* Set layout.backgroundColor default nil
* Fixes buttons color missing options
* Fix unit test
* fix button color parsing
* Moved default options to presenters
* default options fixes
* Fixes e2e
* Fixes unit tests
* Resolve child options on childWillAppear
* Recrusively setDefaultOptions on rootViewController tree
* Fixes default values
* Fixes tests