nodePackages.np: init at 7.0.0

[phryneas]

Motivation for this change

np is a cli util that allows publishing to npm with additional checks compared to npm publish or yarn publish

Things done

• Added np to node-packages.json.
• Ran (cd pkgs/development/node-packages && ./generate.sh).
• Built & installed the new package locally.
• Used it locally.

• Tested using sandboxing (nix.useSandbox on NixOS, or option sandbox in nix.conf on non-NixOS linux)
• Built on platform(s)
  • NixOS
  • macOS
  • other Linux distributions
• Tested via one or more NixOS test(s) if existing and applicable for the change (look inside nixos/tests)
• Tested compilation of all pkgs that depend on this change using nix-shell -p nixpkgs-review --run "nixpkgs-review wip"
• Tested execution of all binary files (usually in ./result/bin/)
• Determined the impact on package closure size (by running nix path-info -S before and after)
• Ensured that relevant documentation is up to date
• Fits CONTRIBUTING.md.

[SuperSandro2000]

PR got combined with a few other node updates. Closing so that the update goes trough smoothly.