* Preparing some scaffolding for video thumbnails
* Implemented thumbnail generation for videos
* Propagating errors of `Node` creation
* Using ffmpeg feature gate
* Introducing ffmpegthumbnailer-rs as a subcrate on core
* - rename to thumbnailer
- fix explorer thumbnail bug
- add more supported video types
- re-fix explorer performance
* remove nested licence
Co-authored-by: Jamie Pine <ijamespine@me.com>
