nav: remove environmentObjects

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.

damus/Views/TimelineView.swift

@@ -8,7 +8,6 @@
 import SwiftUI
 
 struct TimelineView: View {
-    @EnvironmentObject var navigationCoordinator: NavigationCoordinator
     @ObservedObject var events: EventHolder
     @Binding var loading: Bool
 
@@ -28,7 +27,6 @@ struct TimelineView: View {
                     .frame(height: 1)
                 
                 InnerTimelineView(events: events, damus: damus, filter: loading ? { _ in true } : filter)
-                    .environmentObject(navigationCoordinator)
                     .redacted(reason: loading ? .placeholder : [])
                     .shimmer(loading)
                     .disabled(loading)