Support for iPhone XS, XS Max and XR, updates and fixes

[felipowsky]

• Added iOS 12
• Added new screen sizes
• Fixed comparison with unknown. If any of the values of the comparison is unknow, the result is always false.
• Added iPhone XS, iPhone XS Max and iPhone XR
• Simplified execution of property type of the Device
• Added isNotched that returns if the device has a notch or not
• Removed some default cases for switchs so when adding a new case it is easier to find where to make changes
• Version based on version code for iPhone XS, iPhone XS Max and iPhone XR

[anatoliyv]

@felipowsky Thank you for great PR!