Add ""Play file while it's still downloading" option

[trimechee]

Hello, thank you for this awesome great downloader ! 💯 🥇

I have request please : many download manager accelerators have number of threads= 3 or more and we would like to see a "preview video" option play files while it's still downloading because sometimes the video can have a very large size and we have to wait a long time before being able to see the video, there are streaming videos which are not in complex dash or hls format so we can watch them during the download and even with Number of threads: 1, the downloading is very very fast from many streaming platforms despite number of threads is 1..... in addition Number of threads = 1 perhaps allows us to avoid a possible IP ban its we download a lot of the same site......

Thank you so much :)

May be these rare great open source extensions could help and be integrated to Persepolis to detect embed videos from many streamng sites :

https://github.com/chandler-stimson/live-stream-downloader
https://github.com/54ac/stream-detector
https://github.com/puemos/hls-downloader
https://github.com/ray-lothian/Easy-Video-Downloader
https://github.com/inbasic/bulk-media-downloader
https://github.com/inbasic/turbo-download-manager-v2
https://github.com/zaidka/cliget