Denormalize count of episodes into tv-series program

* schema: Move program.tvSeriesCriteria and program.tvSeriesLegacyAgeLimit into program.episodes: { count, criteria, legacyAgeLimit }
* Show episode count from denormalized version when rendering program-box for a series, and only load episodes once episode list is clicked open
* Show spinner when loading episode list (bold&beautiful has > 400 episodes...)
Do not show delete-program-button to root when program is a series containing episodes