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

internal/notification/messages/json.go

@@ -10,8 +10,8 @@ import (
 var _ channels.Message = (*JSON)(nil)
 
 type JSON struct {
-	Serializable    interface{}
-	TriggeringEvent eventstore.Event
+	Serializable        interface{}
+	TriggeringEventType eventstore.EventType
 }
 
 func (msg *JSON) GetContent() (string, error) {
@@ -19,6 +19,6 @@ func (msg *JSON) GetContent() (string, error) {
 	return string(bytes), err
 }
 
-func (msg *JSON) GetTriggeringEvent() eventstore.Event {
-	return msg.TriggeringEvent
+func (msg *JSON) GetTriggeringEventType() eventstore.EventType {
+	return msg.TriggeringEventType
 }