locale property Null safety

1. flutter_json_widgets
2. widget
3. Text
4. locale property

Text class

1. Constructors
2. Text
3. fromJson
4. Properties
5. copyWith
6. data
7. hashCode
8. key
9. locale
10. maxLines
11. overflow
12. runtimeType
13. selectionColor
14. semanticsLabel
15. softWrap
16. strutStyle
17. style
18. textAlign
19. textDirection
20. textHeightBehavior
21. textScaleFactor
22. textWidthBasis
23. Methods
24. map
25. mapOrNull
26. maybeMap
27. maybeWhen
28. noSuchMethod
29. toJson
30. toString
31. when
32. whenOrNull
33. Operators
34. operator ==