insights: track 4.0 aggregation feature usage via pings

Created by: Joelkw

RFC TBA – 

We will want to track:

1. Number of data hovers
2. Number of bar clicks/to filter
3. Number of clicks through to "create insights"
4. Number of insights created (** new, session-like tracking) from that page
5. Number of capture-group type searches where this runs proactively

/cc @joelkw @felixfbecker @vovakulikov @unclejustin