Postgres-backed implementation of ExDav.Storage. Owns its own users, calendars, calendar objects, and tombstones tables; the Repo module is configured via config :ex_dav, repo: MyApp.Repo.

Returns plain maps to keep the CalDAV plug agnostic of Ecto schemas. Each calendar is shaped as %{name, displayname, description, components, ctag, objects} and each object as %{name, ical, etag, uid, component}.