CorrectnessCategory constructor Null safety

1. fact_browser
2. utilities
3. CorrectnessCategory
4. CorrectnessCategory constructor

CorrectnessCategory class

1. Constructors
2. CorrectnessCategory
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static properties
12. correct
13. fabricatedContent
14. falseContext
15. falseInformation
16. manipulated
17. misleading
18. satire
19. unverified