npm cli unknown config warning/cleanup

[wraithgar]

Epic

npm needs to start warning when it encounters config values that aren't defined. This is so folks are no longer surprised when they do things like npm install --loglevl.

This does also mean cleaning up the places we're still using undeclared config. We need to either define them, or formalize some way to have them ignored.

We also want to validate config values that are parsed from files. Currently only cli flag values are validated.

• [FEATURE] Add a handler for *unknown* options, analogous to invalidHandler nopt#41
• [BUG] config var "node-gyp" not respected in npm 7 cli#2839
• fix: allow overriding npm_ env vars via env  run-script#222
• Warn/error on unecessary config items in publishConfig #932
• Validate config from files #653