[Feature] support lightbox

[chirag04]

Just like showAlert we can support showLightBox. showLightBox api can be similar to push except the animation works out of the box for lightbox?

Took the idea from react-native-navigation:

this.props.navigator.showLightBox({
 screen: "example.LightBoxScreen", // unique ID registered with Navigation.registerScreen
 passProps: {}, // simple serializable object that will pass as props to the lightbox (optional)
 style: {
   backgroundBlur: "dark", // 'dark' / 'light' / 'xlight' / 'none' - the type of blur on the background
   backgroundColor: "#ff000080" // tint color for the background, you can specify alpha here (optional)
 }
});

cc @skevy @brentvatne

[brentvatne]

seems reasonable

[sibelius]

@chirag04 take a look on this: https://github.com/oblador/react-native-lightbox