Feature: Add __rich__ method to PlexLibraryItem

[glensc]

Requires: #659

[glensc]

Added manually so far:

• Use rich links when printing titles #1447
• Feature: Use rich links in print_plan #1448

[simonc56]

I see that links are printed 'as is' in file logs with all markup characters :

2023-05-12 04:20:11,431 INFO[PlexTraktSync]:Sync Show sections: ['[link=https꞉//app.plex.tv/desktop/#!/media/3f48753c4e05fda84b1316596945dd36194e4/com.plexapp.plugins.library?source=2][green]TV Shows[/][/]']
2023-05-12 04:20:18,092 INFO[PlexTraktSync]:[link=https꞉//app.plex.tv/desktop/#!/media/3f48753c4e05fda84b1316596945dd36194e4/com.plexapp.plugins.library?source=1][green]Films[/][/] processed in 6.7 seconds
2023-05-12 04:21:01,117 INFO[PlexTraktSync]:Marking as watched in Plex: [link=https꞉//app.plex.tv/desktop/#!/server/3f48753c4e05fda84b1316596945dd36194e4/details?key=/library/metadata/5098][green]Les Mystérieuses Cités d'or/s01e09/La fin du Solaris (1982)[/][/]
2023-05-12 04:21:23,406 INFO[PlexTraktSync]:[link=https꞉//app.plex.tv/desktop/#!/media/3f48753c4e05fda84b1316596945dd36194e4/com.plexapp.plugins.library?source=2][green]TV Shows[/][/] processed in 1 min 5.3 seconds

[glensc]

that is expected