Add more information to worker response to facilitate post-processing

What does this MR do and why?

This MR adds more information to the worker response to facilitate post-processing, e.g. in Kibana, by allowing breakdown by individual workers. It also allows checking the range of processed build IDs.

EE: true

Once we have this in production, we can adapt the query in ClickHouse import workers panel on the Runner fleet management Kibana dashboard to perform a breakdown by worker index:

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested.

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MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.