A simple desktop application for YouTube to Mp3 converter

Uses a yt-dlp which is a YouTube download manager for video and audio. Settings for embedding the download manager is in the class YtMp3.ydl_opts of main.py, it uses a QtCore.pyqtSignal with YtMp3.progress_hook to get the logs or callbacks of the yt-dlp itself when the downloading begins.

More importantly, to avoid freezing, this also inherits a function (run) from the QtCore.QThread to implement background processing.