Add option to respect/ignore safe area on iOS

# Feature Request

## Motivation Behind Feature
Design of some applications requires to show content all over display, including space, reserved for system status bar (for example Google Maps). On iOS Cordova allows to use this space for its html body, but inappbrowser ignore this fact and use only safe area part of body.

## Feature Description
Add "respect-safe-area" option with default value true. If it's true - to keep everything as is. If it's false - use for inappbrowser all body area, no matter if it respects safe area or not.

## Alternatives or Workarounds
As I know, there are no workaround right now.

Start by locating the iOS InAppBrowser option handling and the safe-area layout behavior described in the issue. Trace how an option reaches the native iOS view, then verify the default true and false cases; done means existing behavior is preserved by default and false uses the full body area.

Written by the indexing model from the issue text.