Kibana: [Reporting] More verbose activity indicators during job processing

[tsullivan]

When a reporting job is "processing" it is doing a number of things:

1. Increment the attempts counter in the job data (starting with 1 as the first attempt)
2. Attempt to generate the output within the timeout time
3. If timeout runs out, or there was a failure in generating the report or storing the report data, we wait for a time specified by xpack.reporting.queue.timeout (which is undocumented) and try again.
4. If attempts >= maxAttempts, the job is marked as failed

When generation is successful, the job status goes from processing to completed.

During the time that status is completed, we need to show more information in the Report listing about:

• How many attempts have happened
• If the job is in its "wait before retry" time, we need to show what time the next attempt will occur

We also need to document that xpack.reporting.queue.timeout is used as the "wait before retry" time.

[elasticmachine]

Pinging @elastic/kibana-app

[joelgriffith]

Starting on this.

[axrayn]

It would be fantastic if the document in the .reporting index would also list the node name/ip of the Kibana instance that picked up the job.

This would allow users to identify things like a particular Kibana instance being misconfigured causing report generation to fail.

[tsullivan]

node name/ip of the Kibana instance

We can do that. @joelgriffith let's have it be the UUID of the Kibana instance (which is guaranteed to be unique) as well as the server.name (not guaranteed to be unique).

We can do a truncated UUID if that works out better.

[joelgriffith]

I've got a start here: https://github.com/elastic/kibana/pull/26930, ~need to plumb up the kibana instance/name for this still, currently not recorded atm in the job~. DONE

[joelgriffith]

PR is merged, going to work on back-porting them soon