[SharedUX] Dashboard engagement metrics

[kevinsweet]

The gist
Let's add a new flyout view for dashboards that shows user engagement metrics for admins

Value
Admin users may like to know if dashboards are still used for cleanup/management purposes. For example, they may see that a dashboard hasn't been used in 2 months and has had very little traffic, all time. They may see that "Robert" created it and reach out to him, asking if it's OK to delete.

Requirements
The following are tracked and displayed per dashboard

• Created by
• Last updated by
• Last accessed by
• Total views count
• Total views graph over time (this may seem like a bell/whistle but I'd argue it is actually the only one that really matters in solving the goal -- you need to be able to see total traffic AND recent -- the graph provides both).

Design
See slide 16

[teresaalvarezsoler]

@kevinsweet we need to define what "total view counts" mean. We probably need to set some time limit, e.g. last year.

[elasticmachine]

Pinging @elastic/appex-sharedux (Team:SharedUX)