Merge bitcoin/bitcoin#34342: cli: Replace libevent usage with simple http client

d61053d97b build: Drop libevent from bitcoin-cli link libraries (Fabian Jahr)
798d051c80 cli: Remove libevent usage (Fabian Jahr)
376e7ef07c util: Expose IOErrorIsPermanent in sock header (Fabian Jahr)
5d562430de netbase: Add timeout parameter to ConnectDirectly (Fabian Jahr)
a988ac592f cli: Add HTTPResponseHeaders class for parsing response headers (Fabian Jahr)
c471c5085b common: Add unused UrlEncode function (Fabian Jahr)
9687ef1bd9 ci: Tolerate unused free functions in intermediate commits (Fabian Jahr)

Pull request description:

  Part of the effort to remove the libevent dependency altogether, see #31194

  This takes the parsing logic from the [`HTTPHeaders` class](d549f01caa) from #32061 and puts it into `bitcoin-cli` as a small `HTTPResponseHeaders` class with a comment to revisit potentially sharing this code somehow. This decoupled the two pulls which seems like the most sensible way to deal with this since the actual overlap is very small compared to the impact of each of the pulls which should ideally not block each other.

  Otherwise the change itself replaces the libevent-based HTTP client with a simple synchronous implementation which uses the `Sock` class directly.

ACKs for top commit:
  hodlinator:
    re-ACK d61053d97b
  theStack:
    re-ACK d61053d97b
  w0xlt:
    ACK d61053d97b

Tree-SHA512: a3580a45faf540ee844aac8cb1dc056a89e8e11b45781d2807baa4736d5c0934284c6066206101b6984111a48a186d67845545d07639b623cb35ccc2d85d3ab2

src/netbase.cpp

@@ -587,7 +587,12 @@ static void LogConnectFailure(bool manual_connection, util::ConstevalFormatStrin
     }
 }
 
-static bool ConnectToSocket(const Sock& sock, struct sockaddr* sockaddr, socklen_t len, const std::string& dest_str, bool manual_connection)
+static bool ConnectToSocket(const Sock& sock,
+                            struct sockaddr* sockaddr,
+                            socklen_t len,
+                            const std::string& dest_str,
+                            bool manual_connection,
+                            std::chrono::milliseconds timeout)
 {
     // Connect to `sockaddr` using `sock`.
     if (sock.Connect(sockaddr, len) == SOCKET_ERROR) {
@@ -600,7 +605,7 @@ static bool ConnectToSocket(const Sock& sock, struct sockaddr* sockaddr, socklen
             // synchronously to check for successful connection with a timeout.
             const Sock::Event requested = Sock::RECV | Sock::SEND;
             Sock::Event occurred;
-            if (!sock.Wait(std::chrono::milliseconds{nConnectTimeout}, requested, &occurred)) {
+            if (!sock.Wait(timeout, requested, &occurred)) {
                 LogInfo("wait for connect to %s failed: %s\n",
                           dest_str,
                           NetworkErrorString(WSAGetLastError()));
@@ -643,6 +648,13 @@ static bool ConnectToSocket(const Sock& sock, struct sockaddr* sockaddr, socklen
 }
 
 std::unique_ptr<Sock> ConnectDirectly(const CService& dest, bool manual_connection)
+{
+    return ConnectDirectly(dest, manual_connection, std::chrono::milliseconds{nConnectTimeout});
+}
+
+std::unique_ptr<Sock> ConnectDirectly(const CService& dest,
+                                      bool manual_connection,
+                                      std::chrono::milliseconds timeout)
 {
     auto sock = CreateSock(dest.GetSAFamily(), SOCK_STREAM, IPPROTO_TCP);
     if (!sock) {
@@ -658,7 +670,7 @@ std::unique_ptr<Sock> ConnectDirectly(const CService& dest, bool manual_connecti
         return {};
     }
 
-    if (!ConnectToSocket(*sock, (struct sockaddr*)&sockaddr, len, dest.ToStringAddrPort(), manual_connection)) {
+    if (!ConnectToSocket(*sock, (struct sockaddr*)&sockaddr, len, dest.ToStringAddrPort(), manual_connection, timeout)) {
         return {};
     }
 
@@ -687,7 +699,12 @@ std::unique_ptr<Sock> Proxy::Connect() const
     memcpy(addrun.sun_path, path.c_str(), std::min(sizeof(addrun.sun_path) - 1, path.length()));
     socklen_t len = sizeof(addrun);
 
-    if(!ConnectToSocket(*sock, (struct sockaddr*)&addrun, len, path, /*manual_connection=*/true)) {
+    if (!ConnectToSocket(*sock,
+                         (struct sockaddr*)&addrun,
+                         len,
+                         path,
+                         /*manual_connection=*/true,
+                         std::chrono::milliseconds{nConnectTimeout})) {
         return {};
     }