type property Null safety

1. macro_builder
2. definition
3. FieldType
4. type property

FieldType class

1. Constructors
2. FieldType
3. Properties
4. hashCode
5. isAbstract
6. isExternal
7. name
8. runtimeType
9. type
10. Methods
11. noSuchMethod
12. toString
13. Operators
14. operator ==