cowState property Null safety

1. farmershands
2. home_screen
3. HomeScreenState
4. cowState property

HomeScreenState class

1. Constructors
2. HomeScreenState
3. Properties
4. context
5. cowGroupState
6. cowState
7. farmState
8. groupMenuViewHeight
9. hashCode
10. mounted
11. reportState
12. runtimeType
13. vm
14. widget
15. Methods
16. activate
17. build
18. deactivate
19. debugFillProperties
20. didChangeDependencies
21. didUpdateWidget
22. dispose
23. forceRender
24. initState
25. noSuchMethod
26. onWillPop
27. reassemble
28. setState
29. toDiagnosticsNode
30. toString
31. toStringShort
32. Operators
33. operator ==