[Sign in with Apple] Token revocation not supported in Auth Emulator

When deleting an account of a user that has signed in using Sign in with Apple, Apple stipulates that the app developer also revokes the user's access/refresh tokens. This has been implemented in GCIP, and is exposed on the Firebase Apple SDK (JavaScript and Android SDK pending).

We should implement this on the Emulator as well - people are trying to use this, and receive errors when calling the API:
* https://github.com/firebase/firebase-ios-sdk/issues/11469
* https://github.com/firebase/firebase-ios-sdk/issues/9906#issuecomment-1528679012

Internal: backend implementation in [cl/517195342](http://cl/517195342)
Googlers: see [go/firebase-emulator-siwa-token-revocation](https://goto.google.com/firebase-emulator-siwa-token-revocation)