Add context to in-app system notifications about failed notifications

In the Graylog app itself, failed notifications throw a system notification that look like this:

This gives dear admin very little to work with, especially since the ID shown isn't searchable:

In server.log, more information is given, such as the actual name of the notification, plus when it will be retried:

To avoid having to ask dear admin to search server.log, please add the same information to the in-app system notifications.

## Your Environment

* Graylog Version: 7.0.0-beta.2
* OpenSearch Version: Data Node 7.0.0-beta.2
* MongoDB Version: 8.0.14
* Operating System: Debian 12
* Browser version: Chrome Version 141.0.7390.54 (Official Build) (arm64)