feat: Make Amplitude publish fail gracefully

[spalmurray-codecov]

This PR adds an _unsafe_publish method to the Amplitude event publisher, converting the existing publish method to be safe by default (i.e., it will always fail gracefully).

Also adds prometheus metrics to track success and failures of amplitude publish calls.

[codspeed-hq]

CodSpeed Performance Report

Merging #531 will create unknown performance changes

_{Comparing spalmurray/safe-amplitude (c8494ae) with main (0222015)}

Summary

⚠️ No benchmarks were detected in both the base of the PR and the PR.\

[nora-codecov]

except Exception is broad - every type of raised error will qualify. Can you make it more specific?
If not, it looks like you're swallowing the error (nothing is raised) - is this how you want it to work?

[spalmurray-codecov]

This is the intention yes. The only code below this is the little logic in this file and the underlying amplitude library. We are adding the error details to the log and the counter, so in theory we can catch unexpected errors getting swallowed here.

The end goal of this PR is to make certain calling publish will never error out so we can put it wherever we want with 0 risk of interrupting critical flows.

[nora-codecov]

I see, that makes sense. awesome!

[nora-codecov]

left some thoughts, other than that lgtm!