Implement Video Input Support

[Tsubajashi]

Is your feature request related to a problem? Please describe.
Implementing a way to upscale an entire video through the Interface, instead of a picture.

Describe the solution you'd like
Drag and Drop Support for Videos.

Describe alternatives you've considered
I currently use a waifu2x implementation called "dandere2x", which is fast, but can result into blocky artifacting if the source material isn't on par with the block matching system of dandere2x. i would love to have a quick way to use the "real" waifu2x implementation for videos without CLI.

Additional context
Just wanted to say thanks for the software, its working pretty good for images :)