…xtended logs about the HTTP transaction (nicolas-grekas)This PR was submitted for the master branch but it was merged into the 4.3 branch instead (closes#31641).Discussion----------[HttpClient] make $response->getInfo('debug') return extended logs about the HTTP transaction| Q             | A| ------------- | ---| Branch?       | master| Bug fix?      | no| New feature?  | yes| BC breaks?    | no| Deprecations? | no| Tests pass?   | yes| Fixed tickets | -| License       | MIT| Doc PR        | -This maps the `CURLOPT_VERBOSE` mode of curl to the `debug` info and emulates it when using `NativeHttpClient`.For example:```* Found bundle for host http2-push.io: 0x56193881ae40 [can multiplex]\n* Re-using existing connection! (#0) with host http2-push.io\n* Connected to http2-push.io (216.239.38.21) port 443 (#0)\n* Using Stream ID: 3 (easy handle 0x5619388fcd50)\n> GET /css/style.css HTTP/2\r\nHost: http2-push.io\r\nUser-Agent: Symfony HttpClient/Curl\r\nAccept-Encoding: deflate, gzip\r\n\r\n< HTTP/2 200 \r\n< date: Mon, 27 May 2019 18:23:23 GMT\r\n< expires: Mon, 27 May 2019 18:33:23 GMT\r\n< etag: "0CqJow"\r\n< x-cloud-trace-context: 543375291bd3b71b67fe389260ad1fbd;o=1\r\n< content-type: text/css\r\n< content-encoding: gzip\r\n< server: Google Frontend\r\n< content-length: 1805\r\n< cache-control: public, max-age=600\r\n< age: 0\r\n< \r\n* Connection #0 to host http2-push.io left intact\n```Commits-------1214609 [HttpClient] make $response->getInfo('debug') return extended logs about the HTTP transaction

…ekas, weaverryan)This PR was merged into the 4.3 branch.Discussion----------[HttpClient] add note about getInfo(debug)As implemented insymfony/symfony#31641Commits-------0278830 fixing syntaxb05f9ca [HttpClient] add note about getInfo(debug)