Start to make episodes downloadable
Fix wrong name for resource file
Add todo
Introduce EpisodeManager to handle the actual download
Get downloads going
Add another todo
PodcastManager should only save podcast list to filesystem if needed
Persist episode metadata to make downloads state permanent
Review and refactor new download code, start connecting the UI
Connect downloads and episode manager back to the controller and the UI
Handle download events in the UI
Add proper download icons, add to episode manager housekeeping
Add toasts, add download icons to episode list items
Introduce some housekeeping for downloaded episodes
Prepare for select all downloads
Implement show download
Connect downloads to the UI
Make notification selection actually work, escape episode description
Introduce episode list context mode
finish download functionality