Manifest version 2 is deprecated

[scottbecker]

fyi there is a warning:

"Manifest version 2 is deprecated, and support will be removed in 2023. See https://developer.chrome.com/blog/mv2-transition/ for more details."

[interactiveRob]

@scottbecker thanks for bringing this to my attention. I am busy but will try to get some eyes on this, it says Manifest v3 will disallow remote code, which we likely need because the fix revolves around requesting Google's cast_sender scripts.

But we aren't gunning for app store approval either... so manifest 3 could potentially work if it doesn't hard-block script requests.