Video Lingo dual subtitles

8/5/2024

Fix some errors and implement some features according to user requests:
- Supports Pinyin for Chinese. E.g. 你好嗎 ？ => Nǐ hǎo ma?
- Remove thumbnail when video is paused
- Show previous subtitle lines
- Change subtitle transition effect time
- Change subtitles font size
- Share VideoLingo URL
- Receive sharing from Youtube App, Youtube URL