[Saved Objects] Report usage and last used date

[a03nikki]

Describe the feature:
It would be nice if Kibana could report usage metrics particularly a last used date of the saved objects or content that has been built. For example, something as simple as this

Describe a specific use case for the feature:

This information could be used for multiple purposes

• Further end user education about how to use Kibana or dashboards they should be using
• Know what content is no longer used so it can be deleted instead of maintained
  • For example, do all 100 dashboards + 200 saved searches need to be updated, or is the number much smaller if I make this mapping change?
• Evaluate where to invest more time and money
  • Do I want to invest time improving the most used dashboards? Or the least used dashboards?
  • Are folks using Kibana to review their logs, metrics, and other data? Or are they just ssh'ing into the servers and grep'ing their log files?

Operationally, groups that are responsible for ingest and capacity management of the Elastic Stack would like to know what is being used and not so they can focus their limited resources on the highest ROI (return on investment) opportunities. Right now, Kibana does not provide any insights into what is being used.

[elasticmachine]

Pinging @elastic/kibana-core (Team:Core)

[lukeelmers]

I think this issue mostly duplicates the features outlined in #9202 and #81130, however I'll go ahead and keep it open as this is more focused on some specific enhancements to the saved objects management UI, which would be unblocked by addressing the other two issues.

cc @sixstringcode @arisonl for awareness, as this fits in with the general discussion around saved objects metadata.

[rayafratkina]

We have recently implemented 2 related enhancements as part of #183687

1. Last updated date and last updated by are now shown
2. We show basic usage counters

There are no plans at this time to add more usage data, so I am closing this issue.