copied from csells/go_router#330

GoRouter as of now is lacking behind the current methods available by the flutter navigator.

Currently missing to get at least the basics completely working:

• Navigator.removeRoute https://api.flutter.dev/flutter/widgets/Navigator/removeRoute.html
• Navigator.popUntil https://api.flutter.dev/flutter/widgets/Navigator/popUntil.html
• Navigator.pushAndRemoveUntil https://api.flutter.dev/flutter/widgets/Navigator/pushAndRemoveUntil.html
• Navigator.replace https://api.flutter.dev/flutter/widgets/Navigator/replace.html