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


on IRC mostly, we were discussing the renamer logic changes I did back then.

Basically when we have:
Continuum.S03E13.Last.Minute.720p.WEB-DL.AAC2.0.H264.mkv

We don't want drone to rename it with DRONE as release group. But that depends on the naming pattern.

{Series.Title}.S{season:00}E{episode:00}.{Episode.Title}.{Quality.Title}-{Release Group}
obviously would result in a tailing -, so that's not pretty.

{Series.Title}.S{season:00}E{episode:00}.{Episode.Title}.{Quality.Title}{-Release Group}
would work, since the - is not included if the release group is null/empty. (yes, advanced pattern)
However, we can't use change Release Group coz that would break backward compatibility.
Adding another tag might not be the best option though.

We could just use the m lambda param to check if there are pre/suffixes (m is a TokenMatch object that has that information). If there are, then don't use DRONE.
maybe something like:
```m => episodeFile.ReleaseGroup ?? (!m.HasPrefixOrSuffix ? "DRONE" : null)```