Perform measurements to concretely understand snowflake throughput and network health
We know that there are several proxies that don't seem to work once connected (legacy/trac#31960 (moved)) and that connections are very slow on Windows and possible all platforms (legacy/trac#31971 (moved)).
It would help to be able to quantify this and actively monitor it. There are two things we want to measure: the number of snowflakes that work at all, and the throughput of a sample of snowflakes.
Perhaps something like onionperf can help us out here, but we'll have to see whether onionperf works well with snowflake when we get bad proxies or disconnect.