handle
Process and respond to a server-delivered account update message
💾 This method alters the persisted account state.
Applications should call this method whenever they receive a push notification from the Firefox Accounts server. Such messages typically indicate a noteworthy change of state on the user's account, such as an update to their profile information or the disconnection of a client. The `FirefoxAccount` struct will update its internal state accordingly and return an individual `AccountEvent` struct describing the event, which the application may use for further processing.
It's important to note if the event is `AccountEvent::CommandReceived`, the caller should call `FirefoxAccount::poll_device_commands`