Surface worker requests in performance diagnostics

[adamraine]

response-compression and uses-optimized-images needed to explicitly ignore worker requests in #14212 to maintain their same behavior. That being said, we could analyze worker requests in these audits if we wanted to.

The justification for ignoring OOPIF is that developers don't have as much control over the requests in third parties (#7640 (comment)). However, web workers can be first party so it's reasonable to expect developers to optimize the requests coming from first party web workers.

Previous discussions
#7640
#7795

[adamraine]

From discussion: We want some sort of indicator that the flagged requests are from a worker instead of the page. (e.g. DevTools adds a cog)