cli: add --use-env-proxy

This does the same as NODE_USE_ENV_PROXY. When both are set,
like other options that can be configured from both sides,
the CLI flag takes precedence.

PR-URL: https://github.com/nodejs/node/pull/59151
Fixes: https://github.com/nodejs/node/issues/59100
Reviewed-By: Ilyas Shabi <ilyasshabi94@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

test/client-proxy/test-https-proxy-request.mjs

@@ -92,8 +92,6 @@ if (!common.isWindows) {
     https_proxy: `http://localhost:${proxy.address().port}`,
     HTTPS_PROXY: `http://localhost:${proxy2.address().port}`,
     NODE_EXTRA_CA_CERTS: fixtures.path('keys', 'fake-startcom-root-cert.pem'),
-  }, {
-    stdout: 'Hello world',
   });
   assert.deepStrictEqual(logs, expectedLogs);
   assert.strictEqual(stderr.trim(), '');