[Feature Request] proxy support (like mitmproxy)

### Summary:

using a proxy server has the benefit of not providing the ip to the webpage visiting but you are losing the insight to what an application is connecting to.
so if you would connect directly to the internet with for example firefox, you see that the app is connecting to telemetry/ping hosts. as soon as you enable a proxy you allow the app full internet access.
so it would be awesome to have some kind of mitmproxy embeded in opensnitch, to get some insight and it would be great if the rules would also match for that connections.

firefox -> opensnitch-proxy (rules) -> real-proxy -> target-webpage

i fear this is a big ask but it would be an awesome feature