Regenerate package-lock.json

When running `npm list`, I would get errors about differences between
the installed and specified package. For several packages like next,
msw, and react, the installed version would be older than the specified
versions, by a patch version or two. The packages all had the prefix
'frontend/node_modules' in package-lock.json.

I uninstalled the packages and re-installed them, which put them in the
proper folder.