Implement support for GA4

[philc]

Universal Analytics will stop processing data on July 1, 2023.

[scaledrop]

Yes, We're running out of time. @kitsonk @piscisaureus

Yep we have run out of time for now. GA4 Server side tagging seems to complicated to implement. I think something like a custom analytics service seems like a better option. Similar to cloudflare server side analytics.