Minimal data explorer

[cellio]

https://meta.codidact.com/posts/285446

I am wondering if we can have a minimal data explorer for Codidact communities:

• mirror the publicly available tables/columns in a separate database (can be done once per day to minimize the impact)
• allow logged-in users (maybe have a privilege for this?) to issue read queries with a pretty small timeout (e.g. 10s)
• no fancy editor is required, just a simple text area and a documentation page that shows the relevant tables' schema should be enough as a start

This would allow us to have more advanced information about the community.

We might be able to do this after the server migration. We'll have standby replicas anyway, so maybe they can service these kinds of requests, with the understanding that this data explorer can disappear temporarily if we need those servers to do their day jobs?