Add honu's API health check as a census service health check

[Maelstromeous]

Graciously Varunda has provided an API for their implementation of a Census health check, which is a bit more detailed / ellobarte than ours. https://wt.honu.pw/api/health

We can use this as a confirmation / early warning that Census is having problems. We can use this to confirm from our own checking Census is having problems and act accordingly to ensure it's not just us having the issue.

Additionally, mark the alert as "corrupt" adding a flag to it to say that some statistics may be missing due to Census instability on the website.