P: DNG Converter: Enable JPG conversion

Wow, I was not expecting this to happen anymore after 11 years 😅
However, I thank you so much! The whole timelapse community will benefit from the performance gain this will allow us to take profit of (the work around I came up years ago, required using an external tool, which of course slowed down the workflow).

Would you consider adding TIFF support too? I guess, this should be a similar implementation, since the logic seems to be there already. Thank you again so much for picking this up and implementing it! 🤗