HyperTrack constructor Null safety

1. hypertrack_plugin
2. hypertrack
3. HyperTrack
4. HyperTrack constructor

HyperTrack class

1. Constructors
2. HyperTrack
3. Static properties
4. deviceId
5. errors
6. errorsSubscription
7. isAvailable
8. isAvailableSubscription
9. isTracking
10. isTrackingSubscription
11. location
12. locationSubscription
13. metadata
14. name
15. Static methods
16. addGeotag
17. addGeotagDeprecated
18. addGeotagWithExpectedLocation
19. addGeotagWithExpectedLocationDeprecated
20. locate
21. setIsAvailable
22. setIsTracking
23. setMetadata
24. setName