refactor: remove fs-extra dependency

[ckerr]

Bump Node.js to 14.14.0 to pick up fs.rm(), use it, and drop the fs-extra dependency.

[dsanders11]

This would need to be marked as a breaking change (BREAKING CHANGE: in the commit body).

@electron/wg-ecosystem policy has generally been to avoid Node.js version bumps unless necessary to avoid breaking changes on packages which fragment the install base.

I'd want to look around to see if there are any other breaking changes we can make, like more coe removal as follow-up to #187, etc, if we were going to commit to the breaking change here.

Also, do we want to do a bigger jump, to Node.js 16? I think we need to look at the general ecosystem and see how much we can lift and shift with regards to Node.js version.

[ckerr]

If we're going to move the ecosystem's minimum Node.js version as a whole, v16.7.0 would be nice-to-have to pick up fs.cp()

[ckerr]

@dsanders11 I've pushed up a rebase reword that includes the BREAKING CHANGE text.

+1 on deferring this pending discussion on minimum Node.js version in the ecosystem

[MarshallOfSound]

I've made this case before and will make it again in Ecosystem meetings. Until there is a good forcing function to push us to a higher node version I see only harm can come from bumping the min node version and fragmenting the ecosystem across major versions.

Removing a dependency as ubiquitous as fs-extra isn't a solid reason IMO, because we use it in everything (and lots of other folks do to) it's only installed once normally anyway 🤷 I believe this is on the docket for summit to discuss anyway