feat(android,ios): play from Downloads, and say what a download waits for

- A finished download row on the phones plays when tapped and has an
  Open button for its title, as the desktop's does.
- iOS queued downloads say "Waiting for Wi-Fi" or "Waiting for a
  connection", as Android's already do.
- Android download workers post their notifications as one group, each
  named for its episode, under a "Downloading 12 episodes" summary.
  Before, a season made fourteen loose notifications that all said
  "Making episode available offline".

ios/ProtonStream/UI/TitleView.swift

@@ -462,7 +462,7 @@ private struct EpisodeRow: View {
             if let active = download, active.total > 0, !episode.offline {
                 AccentProgress(progress: Double(active.downloaded) / Double(active.total), solid: scheme.tertiary)
                     .padding(.top, 8)
-                Text(downloadStatusLine(active)).textStyle(.bodySmall).foregroundStyle(scheme.onSurfaceVariant)
+                Text(downloadStatusLine(active, waitingFor: DownloadCoordinator.shared.queueReason)).textStyle(.bodySmall).foregroundStyle(scheme.onSurfaceVariant)
             }
         }
         .padding(.horizontal, 16)