* Merge the AuthenticationServer with the QRCodeLoginService.
* Merge AuthenticationClientBuilderFactory and AuthenticationClientBuilder into AuthenticationClientFactory
The separation is no longer needed now that password/OIDC login and QR code login have a similar API shape.
* Add some tests for DeferredFulfillment with Observation.
* Use StateStoreViewModelV2 in AuthenticationStartScreen.
* Use StateStoreViewModelV2 in ServerConfirmationScreen.
* Use StateStoreViewModelV2 in ServerSelectionScreen.
* Use StateStoreViewModelV2 in SoftLogoutScreen.
* Use StateStoreViewModelV2 in SettingsScreen.
* Use StateStoreViewModelV2 in DeveloperOptionsScreen.
* Use StateStoreViewModelV2 in AdvancedSettingsScreen.