Add Series Options

@kayone @Taloth

This adds the backend support to let us add series and let users choose which episodes to monitor automatically (instead of at a season level) and let them perform a backlog search for missing episodes after adding.

This requires us to listen for two events, the series being added and the disk scan completing. I do feel its a bit fragile right now, since it will do nothing if Sonarr is restarted, the other option is a database table to store it.

No UI or tests in this one, wanted to make sure you guys are good with the approach. Also its specific to this scenario, maybe we need to make it more generic later on, but I didn't want to deal with that unless we require it (I couldn't think of a reason why we would right now).
The point is we're trying to get away from having to select specific seasons, could be done with UI sugar, but then you're just moving the logic to the client.

I think you're right that the names are a bit arbitrary, but they all have valid use cases I think:

- All
- Missing (Episodes without files)
- Future (Any past episodes would be ignored)
- First Season (I want to grab the show to see if its any good)
- Latest Season (The idea here was I only care about the current season, but I'd be fine to drop this one and let it fall into future)