refactor(notification): use new queue package (#9360)

# Which Problems Are Solved

The recently introduced notification queue have potential race conditions.

# How the Problems Are Solved

Current code is refactored to use the queue package, which is safe in
regards of concurrency.

# Additional Changes

- the queue is included in startup
- improved code quality of queue

# Additional Context

- closes https://github.com/zitadel/zitadel/issues/9278

cmd/mirror/projections.go

@@ -221,6 +221,7 @@ func projections(
 		keys.OIDC,
 		config.OIDC.DefaultBackChannelLogoutLifetime,
 		client,
+		nil,
 	)
 
 	config.Auth.Spooler.Client = client