Respect NPM configuration

[aslushnikov]

NPM can define it's own proxy settings, and these are set as process.env.npm_config_https_proxy, process.env.npm_config_http_proxy, and process.env.npm_config_no_proxy.

proxy-form-env does not respect these, and the only way to use these with proxy-form-env is to spoil the global scope:

https://github.com/puppeteer/puppeteer/blob/0b1a9ceee2f05f534f0d50079ece172d627a93c7/install.js#L54-L65

It'd be nice to support these out of the box, or at least have an option to plug them in.

[Rob--W]

@aslushnikov FYI I have published a new version last week, which includes your patch.

[aslushnikov]

@Rob--W thanks! I already picked it up in Playwright :) microsoft/playwright@14a7d1c#diff-b9cfc7f2cdf78a7f4b91a753d10865a2