[Feat. Req.] Fullscreen Background Blur

[momoe]

Just a simple bit of code here to possibly implement into Racoony's CSS settings when loading the Full Screen setting.

https://codepen.io/jonathan/pen/ZWOmmg

This will blur the webpage behind the full-screened image, making it less visually noisy while displaying the image.

I think the blur value should be a user entered variable.

I'm not sure about what the performance impact this would be with the 'Load all Tabs' function of Racoony, so performance testing would need to be planned.

[momoe]

Small addendum, but the loading icon in full screen can use a little polish, so I'm linking some pure css styled loading animations for your consideration. https://loading.io/css/