MongoDB Health System Notification

## What?
- Can we get system notification or errors, in the UI, when MongoDB(single or multi-node) is down or in Recovering.
- Similar to the OpenSearch cluster health notifications.
- Or possibly something on the Node page.
## Why?

- Recently had a two case where customers Archiving was failing because one of their MongoDB nodes was in RECOVERING mode.

- They had no idea that any of MongoDB nodes were having issues, and their archives were failing for several months.
- If they had errors or notifications in the Graylog UI telling them their MongoDB nodes were unhealthy, or down, we may have been able to avoid the archiving issues.

## Your Environment

* Graylog Version: 6.0.5
* MongoDB Version: 5.0.21
* Operating System: Ubuntu

The environment I have the most detail on has
1 load balancer, 3 Graylog nodes, 3 OpenSearch nodes. The three Graylog nodes are also running MongoDB, and replication is configured.