Video-sampler

- added `start-time` and `end-time` options to the `video-sampler` command which allows to specify the start and end time of the video segment to be processed.
- fixed optional imports
- minimal docker builds added

- added multiprocessing over multiple videos in the folder
- new cli command & support reading from `.yaml` config files

- added summary creation from sampled frames

- keyword yt-dlp extraction

- added yt-dlp integration
- extra yt-dlp options are supported

- added blur gating