Allow to choose the image saved quality

Hello and thanks for this great module

I need a better quality for the image that it is saved from youtube since image quality on youtube videos is very low and is manipulated with image styles. Also because of the 4:3 and 16:9 ratios that make that you get black borders if you play them together.

I have looked into the module (I am learning how to program) and I found that you save the 0.jpg version. It would be very nice to be able to choose between default.jpg, hqdefault.jpg, mqdefault.jpg, mqdefault.jpg and maxresdefault.jpg. Maybe, it could be done in the video styles interface.

Thanks again ;)