iconUrl property Null safety

1. soreo
2. user
3. User
4. iconUrl property

User class

1. Constructors
2. User
3. empty
4. Properties
5. description
6. hashCode
7. iconUrl
8. name
9. props
10. runtimeType
11. stringify
12. Methods
13. noSuchMethod
14. toString
15. Operators
16. operator ==