VideoEdit constructor Null safety

1. cloudinary_url_gen
2. video_edit
3. VideoEdit
4. VideoEdit constructor

VideoEdit class

1. Constructors
2. VideoEdit
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Static methods
12. preview
13. trim
14. volume
15. waveform