Implement Element transition on Android

This commit adds basic support for Element transition to Android.
Currently, only Shared Transition is supported and only when pushing screens.

There are a few caveats you need to be aware of if you intend to use
this feature in its current state:

1. Since elements need to be laid out before the transition can start, Set `waitForRender: true` when pushing the destination screen.
2. Fade animation has to be used when pushing screens with shared elements.

API

```js
options: {
  animations: {
    push: {
      waitForRender: true,
      content: {
        alpha: {
          from: 0,
          to: 1,
          duration: 250
        }
      }
    }
  },
  customTransition: {
    animations: [
    ]
  }
}
```

* Refactored backButton api

* Move StackController to separate package

Implement BackButtonOptions

* Somewhat simplify StackController creation in tests

* Pull backButton logic from StackController

* Handle all TopBar button options in TopBarButtons

* fix back button on iOS

* add addicional options to tabbar

* fix tests

* Refactor TopBar options, introduce title options

* Update background to new api

* Refactored topBar options on iOS

* Initial react component in TitleBar android

* set height to react view in TitleBar

* fix tests and lint

* ios unit tests fix

* screen Background Color iOS

* ios v2 topBarTextFontFamily

* added topBarHidden to iOS

* minor fix and topBarHideOnScroll

* minor fix

* topBarButtonColor iOS

* topBarTranslucent iOS

* topBarTranslucent IOS minor fixes

* eslint fixes

* minor fixes

* changed setTabBadge to tabBadge and added a unit test in iOS

* added fontSize on iOS

* minor fix

* topBarTransparent

* minor fix

* first dirty custom transition iOS poc. in need of complete refactor and testing

* dirty poc for view transition

* dirty poc of interactive transition

* deleted unNeeded Files

* cleaning

* cleaning, support for interactiveImagePop and backButton custom transition

* cleaning

* merge v2 into custom-transition-animation fix

* merge fix

* merge fix

* cleaning and merge fix

* support for multiple animation in parralel, animations with are not shared element including: velocity, spring, alpha and translate

* last commit should also include these

* added resize mode animation and fixed flickering bug

* refactoring

* first cleaning and another test

* cleaning

* commandsHandler now accepts bridge in constructor, fixed tests, added e2e test

* eslint

* android pop now recieves two parameters - preparation for custom transition

* Refactor + add afterLoad to modal

* merge v2 second try

* merge fix

* merge fix

* fix ios unit tests

* fixed topBarTransparent e2e

* fix js tests

* refactored RNNAnimator, RNNAnimatedView, small fixes

* refactor topBarLargeTitle

* fixed lifycycle bug with componentWillUnmount, small fixes

* fix transparent conflict

* removered Element.js from coverage report

* comment redundent test
(still needs to be discussed), small fix

* removed commented test, moved element.js to adapters