Add capital feature : Start downloading automatically when clicking on the "parser" icon in the pop up

[trimechee]

Hi, I think half of my lamentation posts is Cat-Catch's github are because I didn't know how to use correctly the m3u8 parser, and Mr Xifangczy have generosity to check my requests and told me everything works fine... sorry :(

I didn't know how to use the m3u8 parser because when I click on the "parser" icon in the pop up, the download doesn't start automatically, and I didn't know we have to look for the button at the bottom "merge and download" and so I always used the button "send to ffmpeg" where I saw different problems trying donwload temporary videos....

I admit that not starting the download automatically can be useful to check the video quality to know if we are going to download standard SD quality or 1080p quality, but we know the index stream v1a1 contains always the worst video quality.....

so to reveal the gigantic hided potential of Cat-Catch which will become the best downloader of the world if jwplayer / videojs object support will be added in the future, we hope please the download in m3u8 parser will start automatically, and also we hope alert will be displayed when all the small hls video fragments slices are downloaded, because even when they are all downloaded, the "stop download" button remains active in m3u8 parser, or fix the problem of the feature : close the tab when download is finished in m3u8 parser, thanks!