PDFKit iOS 12.1 to 12.2 API Differences

PDFKitPlatform.h
Removed #def PDFKitPlatformTextFieldDidBeginEditing
Removed #def PDFKitPlatformTextFieldDidChangeText
Removed #def PDFKitPlatformTextFieldDidEndEditing
Removed #def PDFKitPlatformTextViewDidChangeSelection
Added #def PDFKitPlatformTextViewDelegate