More control in video synthesis

• Now you can make portrait translated subtitled videos from landscape videos.
• You can either choose a picture background, or default to the video's zoomed fuzzing background.
• The ASS style is working great !!
• You can control subtitle's vertical offset. The zoom size of video and/or subtitle. Very useful for portrait videos.
• It seems the AI single translation is working fine. It takes less time and effort compared to the optimize+translate method.
• Now the batch tasks display a lot more information about each task, with some portrait / landscape control.