Feature requests

[Specy]

• Add button to change destination folder next to the open dir button
• Add buttons to see next/previous element when doing the preview d59560d
• Create an interface for the upscalers so that it's easy to add new ones and create an automatic schema recogniser for the settings of each mime type (maybe? Less user friendly but easier to edit) and decouple the waifu2x upscaler from the app
• Add more upscalers and models, possibly as an add-on, or maybe create a store in the app so that upscalers and models can be downloaded from the app itself
• Maybe add more AI tools unrelated to upscaling?