Updates package dependencies to more modern versions, also adds .nvmrc and package-lock.json as followups to [43683] and [43571]. See #44600. Fixes #45064. Built from https://develop.svn.wordpress.org/branches/5.0@43684 git-svn-id: http://core.svn.wordpress.org/branches/5.0@43513 1a063a9b-81f0-0310-95a4-ce76da25c4cd