Simplify with new EventsModel constructors. This is slightly less
typesafe but its not a big deal, I hate inheritence more.
Signed-off-by: William Casarin <jb55@jb55.com>
environment objects are implicit arguments that cannot be checked by the
compiler. They are a common source of crashes. Use a main
NavigationCoordinator in DamusState for the core app, and pass in other
coordinators in the account setup view for the parts of the app that
don't have a DamusState.
