Use `yt-dlp` instead of `curl` to fetch Videos from TikTok

Seems that the current method used by the Backend to fetch the video is not exactly liked by TikTok. I've tested `yt-dlp` to fetch the video, and it seems to actually work just fine. I've done a test on my own backend and so far things are working: https://github.com/Znuff/offtiktokapi/commit/7fe69df8c80af214c2e87cd0d692db5633d4cbcb *warning: this patch is AI generated, not that it matters much*, for production it would probably require many more checks