Lighthouse 9.x needs Node 14. However, Parcel v1 does not work in 14 , and Parcel v2 proved too difficult a migration[1], so let's use esbuild.

There's a esmodule-only plugin used in this PR that requires an upgrade to Node 14 too, so doing that all in the same PR.

[1] some chat logs

• means LHCI needs to bump from node 12->14
• parcel v1 doesnt work in node 14 (no precompiled gyp binaries local compile fails)
• parcel v2 it is!
• yarn workspaces hoists common deps to root node_modules, which flabbergasts parcel v2
• ok, fine, yarn workspaces has a "nohoist" thing, let's use that
• "nohoist" doesn't seem to work at all ... was fixed in yarn 2...