Fixed: Use Nzb title as scene name when available

- Use Nzb title as scene name when available
- Only use file name as scene name when its highly likely that it's an actual scene name
- Don't store `DRONE` as default release group in the DB
- Clean up the db removing obviously wrong scene names


Good choice to move that here.
Might be an idea to add another tag without the default too. Some users have been requesting it, but so far I've been saying that it's stored in the db atm.