Authentication constructor Null safety

1. nevis_mobile_authentication_sdk
2. nevis_mobile_authentication_sdk
3. Authentication
4. Authentication constructor

Authentication class

1. Constructors
2. Authentication
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. authenticatorSelector
8. biometricUserVerifier
9. devicePasscodeUserVerifier
10. execute
11. fingerprintUserVerifier
12. noSuchMethod
13. onError
14. onSuccess
15. pinUserVerifier
16. requestHeaders
17. retryPolicyObtainingAuthorizationProvider
18. sessionProvider
19. toString
20. username
21. Operators
22. operator ==