Summary

This PR will not be merged, please do not comment on naming, any code style/readability issues, or the FR API surface yet. Macro-level approach commentary welcome :)

This PR is intended to give a better sense of how the tiny Fraggle Rock PRs for Phase 1 are meant to come together. It's a cleanish version of just the phase 1 bits from a local FR prototype without tests. It can generate a report of a URL for all audits that only rely on evaluateAsync (all other audits will error). If anything jumps out to you about the way in which FR integrates with the runner, or the fact that we have a new driver that gets passed to our gatherers, that's what is worth discussion at this stage.

Goals of Phase 1 (see #11313 for more detail):

• Enable early end-to-end testing of fraggle rock.
• Minimal disruption to mainline core development.
• Establish migration path for existing gatherers upon which future phases will build.

I'll be breaking the gist of this into PR into several smaller chunks for landing.

Related Issues/PRs
ref #11313 #11623 #11633