windows: Create npm folder in AppData directory

Create the empty npm folder in Roaming\Appdata so that
non-Administrator users have a place to store global packages.
This fixes the error Error: ENOENT, stat error that occurs
when a user tries to run the npm install <package> command.

Fixes #8141
Merge branch 'fix-issue-8141' of https://github.com/rockarts/node into fix-issue-8141