Add hover effect to acceptCookieButton

When we hover on the acceptCookieButton, maybe we should change the background to another color to let the user know the button is clickable?

I had two designs in mind:

Black background on hover: Look & Feel 1

Blue background on hover, this one uses the same color as other button and should make things feel more "consistent". Look & Feel 2

Once we're set on one, I will uncomment and clean up things.