Prevent window focus detection by utilizing the Page Visibility API

[weaponmasterjax]

Is your feature request related to a problem? Please describe.
It's always frustrating when some websites forces people to watch ADs and stay on site for a long period of times. Some others scrambles or changes to misleading titles when the tab is switch elsewhere/window lost focus. We need to

Describe the solution you'd like
Spoof on the Page Visibilty API and make it report to the web page as it's always focused.

Describe alternatives you've considered
Using Tampermonkey userscripts: they sometimes work, but often detectable.