ClassType constructor Null safety

1. macro_builder
2. definition
3. ClassType
4. ClassType constructor

ClassType class

1. Constructors
2. ClassType
3. Properties
4. hashCode
5. isAbstract
6. isExternal
7. isNullable
8. name
9. reference
10. runtimeType
11. scope
12. superclass
13. superinterfaces
14. typeArguments
15. Methods
16. noSuchMethod
17. toString
18. Operators
19. operator ==