Screensaver mode

[mononaut]

Add a URL param flag to open Bitfeed in a screensaver-friendly mode with minimal UI and no static elements to reduce burn-in:

• Set background to #000
• Hide message bar, sidebar, price/network status
• Randomize position of latest block info?

feature request from https://twitter.com/mrbobdobalina20/status/1492949974623174664?s=20&t=8NQ81v9VgqnEWYef3zUmVg