Support for capture cards and new DeepL API

I was bored and added support for allowing the use of capture cards, represented by a new setting within the settings menu to toggle between webcam-based input, which capture cards usually represent themselves as, and application-window-based input, the original option.

Furthermore, I replaced the DeepL jsonrpc calls with the official DeepL API, which requires creating a free DeepL account to get an API key.