Add reports endpoint for checking portal adoption rates
To support some reports that are needed for KPI in association with this project, we should create a new reports endpoint. Usage and requesting of this API will require a logged-in auth state of a user with an @eclipse-foundation.org
account as that is the easiest way to secure this data.
We will want to cache results so that lookups don't create lag on the SQL connections. The first report for this endpoint will be to check membership adoption rates. As we already bind to the table to write login events, this should be a reasonably easy report to generate over all.