The primary benefit of this is to avoid Rocket's database integration,
which has become problematic in this codebase with the update to the
new async style. Because the async database API is actually
synchronous under the hood, this introduces some annoying lifetime
requirements that basically force us to use owned data everywhere.
The original pattern was to have a separate data layer that could
invoke queries from `self` (the db connection). By using a true async
database driver, we can get this back, because the lifetimes are once
again flexible instead of the ones forced by Rocket.
projectmoon