[SRE-87] record-tester: export useful success metrics

[iameli]

There are some metrics exported from record-tester already but probably not the most crucial success/failure metrics. I have no idea what's in there actually.

This task also includes getting Prometheus scraping working for our deployments so the metrics end up in eu-metrics properly.

[pwilczynskiclearcode]

There was a discussion on Discord about VOD E2E Tester of Studio with ... for sin.livepeer.com error: error importing asset from url=https://.....mp4: error waiting for asset processing: error processing task, taskId=... status=failed error=error building task context: not found alert from PagerDuty being too noisy.