Created a favicon workaround

[Gerschel]

@Nacurutu
I modified the css files.
They use the static folder.

I created a workaround so the webui.py file does not need modification to work.

It was a bit tricky.

The issue we kept having was that cors was set to a stricter mode.
But css is behaving less strict, so it can serve a file. But only if it's a background image.

For it to work, the browser needed to see an html element with the background image declaration before load.
So I used a gradio html declaration, and in it I put a div.
Then I targetted that div with css. I also set the div to hidden.
Then with javascript I looked into the div's css computed values. Took that result and piped it into the standard
html link tag that is used to set a favicon.

So you will need to do a pull before you try to push.

Give it a whirl and let me know if it only works on my machine.