RequestServer: Add a CURL_DEBUG flag

This sets `CURLOPT_VERBOSE` to 1, which enables detailed logging of
all cURL connections to stderr.

AK/Debug.h.in

@@ -54,6 +54,10 @@
 #    cmakedefine01 CSS_TRANSITIONS_DEBUG
 #endif
 
+#ifndef CURL_DEBUG
+#    cmakedefine01 CURL_DEBUG
+#endif
+
 #ifndef DEVTOOLS_DEBUG
 #    cmakedefine01 DEVTOOLS_DEBUG
 #endif

Meta/CMake/all_the_debug_macros.cmake

@@ -9,6 +9,7 @@ set(CSS_LOADER_DEBUG ON)
 set(CSS_PARSER_DEBUG ON)
 set(CSS_TOKENIZER_DEBUG ON)
 set(CSS_TRANSITIONS_DEBUG ON)
+set(CURL_DEBUG ON)
 set(DEVTOOLS_DEBUG ON)
 set(DNS_DEBUG ON)
 set(EDITOR_DEBUG ON)

Services/RequestServer/Request.cpp

@@ -339,6 +339,9 @@ void Request::handle_fetch_state()
 
     set_option(CURLOPT_CUSTOMREQUEST, m_method.characters());
     set_option(CURLOPT_FOLLOWLOCATION, 0);
+    if constexpr (CURL_DEBUG) {
+        set_option(CURLOPT_VERBOSE, 1);
+    }
 
 #if defined(AK_OS_WINDOWS)
     // Without explicitly using the OS Native CA cert store on Windows, https requests timeout with CURLE_PEER_FAILED_VERIFICATION