Perf of sync command

[VincentBailly]

The "sync" commands takes around 6min to run on a repo that has 1500 packages. The time is spent spawning child-processes to run the npm cli command to get each package metadata. Perf could be greatly improved here by simply calling fetch to the npm feed endpoint directly in process. This would avoid the creation of 1500 child processes and possibly allow nodejs to better manage the SSL connection(s) used to connect to the feed.