Track via Proxy using flutter

[manoletre]

I was struggling with blockers (see #91) in flutter web. It caused the whole page to crash.

I ended up setting up a proxy server and modifying the default .js script that comes with the package (see my last comment) - things don't break now - but I cannot track users with a blocker active.

It would be great if using a proxy server (see https://docs.mixpanel.com/docs/tracking/how-tos/tracking-via-proxy) would work for flutter as well.