Share limits: Max inactive time

[Minituff]

Hello,

Proposing a new idea for share_limits if it doesn't exist already.

max_inactive_time = Will remove the torrent if it has been inactive for X amount of time.

For example, I could specify I want my torrents to use the min_seed_time for 14 days, but could allow the torrent to continue seeding until it has had no activity for 30 days, then qbit_manage could clean it up.