Metrics: Show "Endpoint" and "Message Type" first / last message seen

[ramonsmits]

Describe the feature.

For operational awareness it would be nice to show:

• Endpoint first message seen
• Endpoint last message seen
• Message type first seen
• Message type last seen

This especially is useful information in environments that have a lot of endpoints that are idle most of the time and provides insights if endpoints and message are actually still in use or could be investigated to be decommissioned.

Additional Context

No response

[ramonsmits]

Solution suggestion

A message analyzer in ServiceControl could inspect incoming audit (maybe also error) messages and update these statistics. These statistics can be asynchronously updated and would not need to be updated to storage for every message received but could be flushed at a fixed interval asynchronously and at (graceful) shutdown/termination to reduce transactional IO pressure.

Alternatively these could be scanned by inspecting existing messages stored in audit/error but as each use only temporarily store message data the metrics could become invalid when messages eventually get purged.