[firebase_auth] Fix crash with null additionalUserInfo (firebase#1588)

* [firebase_auth] Fix crash with null additionalUserInfo

* Add back author field

* fix test

[firebase_messaging] Make onIosSettingsRegistered callback on iOS >= …

…10 (firebase#1565)

[firebase_auth_web] creationTime and lastSignInTime are not parsable …

…by DateTime.parse (firebase#1553)

CreationTime and lastSignInTime are RFC1123, DateTime cannot parse it. Updated to use http_parser.parseHttpDate.

[firebase_crashlytics] Updated the documentation language. (firebase#…

…1551)

* Updated the documentation language.

The english was a bit confusing.

* Update packages/firebase_crashlytics/CHANGELOG.md

Co-Authored-By: Collin Jackson <[email protected]>

[firebase_crashlytics] Updated the documentation language. (firebase#…

…1551)

* Updated the documentation language.

The english was a bit confusing.

* Update packages/firebase_crashlytics/CHANGELOG.md

Co-Authored-By: Collin Jackson <[email protected]>

[firebase_core] Check `kIsWeb` in `firebase_core` (firebase#1487)

* Add kIsWeb check to defaultAppName

* Bump version of firebase_core

* Bump to 0.4.2+1 instead of 0.4.3

[firebase_auth] Add platform interface (firebase#1496)

* Move firebase_auth to firebase_auth/firebase_auth

* WIP on firebase_core_platform_interface

* Fix up tests

* Respond to first round of review comments

* Format

* Respond to 2nd round of review comments

* Rename updatePhoneNumber to updatePhoneNumberCredential

* dartfmt

* Make PlatformUser extend PlatformUserInfo

* Give _PhoneAuthCallbacks a const constructor