Add E2 getter functions

Should include an E2 lib to allow players to retrieve some amount of time data. Sessions maybe? Current session only? We'd have to decide. This is basically just giving access for players to query the DB so we need to be careful about exhaustive searches.

Maybe we could force it to be paginated and include rate limiting or something.

No files, tests, or entry points are named. First clarify whether getters cover current sessions or historical session data, then define pagination, rate limiting, and search limits; the work is done when that API scope and its safety requirements are agreed and implemented.

Written by the indexing model from the issue text.