NERoomBaseController constructor Null safety

1. netease_roomkit
2. netease_roomkit
3. NERoomBaseController
4. NERoomBaseController constructor

NERoomBaseController class

1. Constructors
2. NERoomBaseController
3. Properties
4. hashCode
5. isSupported
6. runtimeType
7. Methods
8. addAttachment
9. clearAttachments
10. getAttachment
11. noSuchMethod
12. removeAttachment
13. toString
14. Operators
15. operator ==