PickUpOutcome_Value constructor Null safety

1. spine_client
2. delivery.pb
3. PickUpOutcome_Value
4. PickUpOutcome_Value const constructor

PickUpOutcome_Value enum

1. Constructors
2. PickUpOutcome_Value
3. Values
4. session
5. alreadyPicked
6. notSet
7. Properties
8. hashCode
9. index
10. runtimeType
11. Methods
12. noSuchMethod
13. toString
14. Operators
15. operator ==
16. Constants
17. values