Include creation UI event logs in backend pings

Created by: felixfbecker

We need to add the backend logic for pings that will send us the data for the recorded event logs we managed to still include in the last release (in https://github.com/sourcegraph/sourcegraph/pull/21177).

My understanding is this involves some Go code running SQL queries to include the aggregated data in pings, and some kind of schema JSON for @ebrodymoore to know how to add this to our analytics pipeline on our end. More details on that in this thread, and also some suggestions on who can help answer questions on how to implement the backend.

Some more pointers:

• Existing insights analytics Go code
• Public documentation on what we track for Code Insights
• RFC for the pings we need