Optimize yarn install --update-lockfile

[mgfalzon]

yarn --mode update-lockfile has a couple of bottlenecks.

• 6s originalWorkspaceDefinitions can we only store the originalWorkspace definitions for the workspaces with peerDependencies?
• 6s allPeerRequests. hasOwnProperty is more efficient than in . We iterate over root.requests.values() twice, I think this can be re-written to iterate once?

Not providing the trace, because I'm unsure if it would contain sensitive information? Probably not, but best to safe than sorry.