Improve logging of failures writing check-ins to Elasticsearch

**Describe the enhancement:**

When a bulk request fails to update the state on Elasticsearch, we log `Eat bulk checkin error; Keep on truckin'`.

It would be useful to tell, in the Logs:
- more info on the requestor (e.g. the agent ID which generated it or other useful tracing info), if possible
- a more actionable message
- having the whole payload which failed in the events logging would help

**Describe a specific use case for the enhancement or feature:**

Better troubleshooting and understanding of the issues

Search for the `Eat bulk checkin error; Keep on truckin'` log and trace the Elasticsearch bulk check-in failure path. Review how agent IDs or tracing data and failed payloads are represented in event logging; done means failures provide actionable requestor context and the relevant failed payload.

Written by the indexing model from the issue text.