Bench cargo scope

Section

db = Chat.Db.db()
room = Chat.Rooms.list() |> Enum.find(&(&1.name == "mar23-cargo-test"))
user = Chat.User.list() |> Enum.find(&(&1.name == "s.32"))

:timer.tc(fn -> Chat.Db.Scope.KeyScope.get_cargo_keys(db, room.pub_key, [user.pub_key]) end)

1. mar30fw sensor (32G sd) = 815-845 ms
2. mar23fw operator (64G usb) = 790-805 ms
3. mar30fw operator (64G usb) = 890-900 ms
4. apr6fw operator (64G usb) = 870-918 ms