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


probably should provide some background on why I'm doing this clean up.

the scene names we have in db are pretty shitty to say the least. we pretty much put anything we can get our hands on in there. for me most of it was filled with my own custom name format. 

with this script I'm trying to clear everything except scene names that are actual scene names with a high level of confidence.

unless we can spot those webdl releases reliably I would rather clear them than to have wrong scene name.

I have a plan that would allow us to grab actual scene names latter if we need them based on file signature but that would rely on us having scene names that are reliable.