* Cleanup and reorganise playground app

* Separated tests into three categories
  1. Layouts - layout specific tests and feature showcase
  2. Options - options related tests; interactions between static and dynamic options, merge options etc
  3. Navigation - general navigation features; Orientation handling, events, Overlay etc

* Fixed a few Android bugs
  1. testID wasn’t applied on TopBar react buttons
  2. static options were disregarded when creating initial BottomTab options
  3. Trying to open a none existent SideMenu would result in a crash

* Fix e2e tests

* Fix lint

* Few fixes + split push from SideMenu test into two tests

* Fixes e2e

This change lets buttons stretch horizontally using padding and
margins and not only by changing width property explicitly.

[BREAKING] Call Navigation.events().bindComponent(this) to listen to lifecycle events

This commit introduces breaking changes to the way components listen to RNN events.


Background

Up until now, components could handle navigation events by implemented a set of callbacks:
* componentDidAppear
* componentDidDisappear
* onNavigationButtonPressed
* onSearchBarUpdated
* onSearchBarCancelPressed

While this worked fine for the most part, this was completely broken for HOCs as RNN invoked these methods only on the registered component (top most HOC), leaving it to the user to propagate these events down the HOC chain. See the discussion in #1642 for more details.


Solution

In order to support HOC use case, we're introducing a new api which will let any Component bind itself to receive navigation events:

```js
class LifecycleScreen extends Component {
  constructor(props) {
    super(props);
    this.subscription = Navigation.events().bindComponent(this);
  }

  componentWillUnmount() {
    // The subscription is removed automatically when components unmount, but they can be explicitly removed as well by calling `this.subscription.remove(); `
  }
}
```

It's still the users responsibility to propagate the `componentId` down the HOC chain, but by binding a component to RNN, it will be able to handle events as expected. Multiple components can be bound for the same `componentId`.


Consolidate event names

* onNavigationButtonPressed -> navigationButtonPressed
* onSearchBarUpdated -> searchBarUpdated
* onSearchBarCancelPressed -> searchBarCancelPressed

* TopBar custom buttons initial commit

* f

* Consolidate TopBarButtonController and TopBarButton

* Move Toolbar related stuff to TitleBar

* TitleBarTest

* More tests