Multi-season support

Is there an existing issue for this?

• I have searched the existing open and closed issues

Is your feature request related to a problem? Please describe

This is yet another proposal for multi-season download support, for those trying to archive or watch completed shows.

Describe the solution you'd like

While there are already similar tickets closed, like #8133 and attempts to solve my issue in #8508 and #8668, I would like to propose a limited and scoped solution for specific (and IMHO most common) scenario:

• Downloading an entire show or multi-season packs using:
  • Interactive search
  • Manually adding category in existing DL client job

I would like to hear from maintainers and other users their opinions on following proposed approach. Keep ignoring MS packs in:

• automatic search
• RSS
• auto-upgrades

Show a warning next to interactive search results, but allow to auto-import it from a DL triggered from such search or externally added to the DL client. This way, we would follow the same experience as manual import would, but need to consider edge cases like mixed qualities, auto upgrades and incomplete seasons.

I am not fully familiar with auto-upgrades feature so I believe some additional restrictions might need to be applied - like forcing users to unmonitor the show first or disable auto-upgrade if season was picked up this way.

Describe alternatives you've considered

Current v4 suffers from "data loss" issue reported in #8133 and v5 now refuses to handle multi-season packs if they were added externally which leaves manual import as the only way of handling such packs. It's much safer now but it means users must manually monitor DL progress and trigger the import once it's done.

Anything else?

I have tried drafting an implementation around comments from #8668 but have not tested it yet. Will submit PR once the discussion is finalised, as per CONTRIBUTING.md.

I am aware that historically multi-season packs support was discouraged but I believe many users would still benefit from that functionality, even by sacrificing auto-upgrades, RSS monitoring or other functionalities for that particular TV Show.

Implementation plan

• Parser: track full season range on multi-season packs - #8941
• ⌛ Resolve episodes across every season in a pack - #8958
• Allow multi-season packs to import completely
• Queue: report every season a download covers