"Unseen" command for ended series should show episodes left

[neonrust]

Preferrably without adding a third line in the output, e.g.:

   19 The Walking Dead  (2010-2022)  ended                             tt1520211  
       Next:  s11e17 Lockdown                                      45min 2022-10-02

Should show e.g.:

   19 The Walking Dead  (2010-2022)  ended   9 left                    tt1520211  
       Next:  s11e17 Lockdown                                      45min 2022-10-02

Maybe it could show episodes left in the current season but also the total.

[neonrust]

This is implemented, although the alignment of the text is wonky (this is a more general overhaul of format_episode_title()).

[neonrust]

Can close this. The above-mentioned alignment isn't really related to this specific feature.