Barcode - iOS safe area

[jtara]

Barcode extension should obey the iOS Safe Area when running on iOS >= 11

[jtara]

See:

• https://stackoverflow.com/questions/48236375/custom-uitoolbar-too-close-to-the-home-indicator-on-iphone-x
• https://medium.com/rosberryapps/ios-safe-area-ca10e919526f
• https://ivomynttinen.com/blog/ios-design-guidelines
• https://developer.apple.com/documentation/uikit/uiview/positioning_content_relative_to_the_safe_area?language=objc