Until now controlling drawers touch gestures was impossible, drawers received gesture opening touch from the entire screen and that causes collisions with other gestures (which are implemented on the javascript side).

This commit adding modes for how sideMenu drawers gestures will receive opening touch.
```
{
  sideMenu: {
    openGestureMode: 'entireScreen' | 'bezel'
  }
}
```

- `entireScreen`: drawer gesture will trigger drawer opening from the entire screen
- `bezel`: drawer gesture will trigger drawer opening only from the center screen bezel frame

The default didn't change.

Add title alignment to options

This adds an Android-only flag blurOnUnmount, that if true when calling push, pop, showModal, dismisModal, as well as when true on the component's static options(passProps) { ... } return value, will cause RNN to check for any focused views when the component the flag was passed for is being unmounted, and blur said view if it exists, causing not just the view to lose focus, but also the soft keyboard to be dismissed.

We added this to our fork of RNN to tackle issues stemming from an inability to dismiss the soft keyboard on unmounting components, due to the disappear/unmount lifecycle events of the component coming too late for our keyboard dismissal calls to make it across the native<->js bridge before the component was unmounted.

As this functionality is hidden behind a flag and does not alter base functionality, and the issue it seeks to solve might have been encountered by other users of RNN, I figured I might as well submit a PR to see if there is interest in merging this back into the base.

* Removed topBar.transparent and added transparent color support for topBar.background.color

* fix unit tests

* Fix ability to add color for back button

* Change docs because color can be used with iOS too

* Simplify code more

* Move icon logic to one function

* Make returning more clear

* Remove title setting because it is in setBackItem

* Make setBackItem function more clear

* Looks like the if is not needed

* Update RNNBackButtonOptions.m

* Update RNNBackButtonOptions.m

** For iOS only

* Added all styling options and WIP comments

* Completed screen options and layout types

* Added typings to the main entrypoint

* Added buttons too

* Optional fields

* Fixes js unit tests

* Added all styling options and WIP comments

* Completed screen options and layout types

* Added typings to the main entrypoint

* Added buttons too