Improved attach mode together unit test

Add iOS support for `bottomTabs.attachMode`.
This property controls when BottomTabs children are attached to hierarchy and when their React views are created.

By default, RNN attaches all children at the same time which might impact loading time as a few screens are instantiated at once.
Using `afterInitialTab` or `onSwitchToTab` generally leads to improved start up time.

* Support centered bottomTab icons using bottomTabs.titleDisplayMode option

* Improve readability, better namings

* Rename setTabItemImagesCentered to centerTabItems

* [V2][iOS] Fix bottomTabs’s animate option

Signed-off-by: wilson <wilson@waveo.com>

* change animated default value to false

Signed-off-by: wilson <wilson@waveo.com>

* fix self.tabBar.hidden value

Signed-off-by: wilson <wilson@waveo.com>

* Fix tests

Signed-off-by: wilson <wilson@waveo.com>

* fix value check

Signed-off-by: wilson <wilson@waveo.com>

* 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

* Support UIBarStyle for topBar and bottomTabs

* Added to docs

* Refactored bottomTab and bottomTabs

* Initial commit before switching to our fork of AHBottomNavigation

* Bump AHBottomNavigation version

* More work on BottomTab options

Need to merge some child options when a child is attached to parent

* Fix tests

* DefaultOptions refactor

* defaultOptions are now merged before applying options
* Handle BottomTab options in dedicated presenter
* Create BottomTabs in BottomTabsController.createView() instead of constructor

* Set bottomTab TypeFace

* Update Android installation guide

* fixed unit tests

* Fix unit tests

Kind of a workaround

* Handle NPE in getPreferredHeight

If a view hasn't been attached yet, return 0 height

* Apply BottomTab text and icon color individually

wix-playground/AHBottomNavigation does not support setting color for the entire tab (icon and text),
instead it supports setting color individually to text and icon. Another change is that it no longer supports
default color for icons. If icon color is undefined - it won't tint the icon.

* Add getCurrentChild to ParentController contract

* Clear backButton when setting stack root

* Add  ViewController.resolveCurrentOptions

resolveCurrentOptions merges the controllers options with all of its current children

* StackController refactor

* Create pushed child view only in StackController.createView
* When initialising a stack with multiple children, only create the top child's view
* StackController constructor now accepts children
* When pushing child to stack, apply options that change LayoutParams

* Apply BottomTabs layout options when tab views are created

* bototmTab changes in iOS

* options fix

* Fixes options propagating

* refactored navigation options

* test fix

* better namings