Add crud endpoints for notifications (#801)

Co-authored-by: kolaente <k@knt.li>
Reviewed-on: https://kolaente.dev/vikunja/api/pulls/801
Co-authored-by: konrad <konrad@kola-entertainments.de>
Co-committed-by: konrad <konrad@kola-entertainments.de>

pkg/user/listeners.go

@@ -40,6 +40,6 @@ func (s *IncreaseUserCounter) Name() string {
 }
 
 // Hanlde is executed when the event IncreaseUserCounter listens on is fired
-func (s *IncreaseUserCounter) Handle(payload message.Payload) (err error) {
+func (s *IncreaseUserCounter) Handle(msg *message.Message) (err error) {
 	return keyvalue.IncrBy(metrics.UserCountKey, 1)
 }