refactor: Coroutine based webserver (#1699)

Code of new coroutine-based web server. The new server is not connected
to Clio and not ready to use yet.
For #919.

tests/common/util/CallWithTimeout.cpp

@@ -0,0 +1,47 @@
+//------------------------------------------------------------------------------
+/*
+    This file is part of clio: https://github.com/XRPLF/clio
+    Copyright (c) 2024, the clio developers.
+
+    Permission to use, copy, modify, and distribute this software for any
+    purpose with or without fee is hereby granted, provided that the above
+    copyright notice and this permission notice appear in all copies.
+
+    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
+    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
+    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+//==============================================================================
+
+#include "util/CallWithTimeout.hpp"
+
+#include <gtest/gtest.h>
+
+#include <chrono>
+#include <cstdlib>
+#include <functional>
+#include <future>
+#include <thread>
+
+namespace tests::common::util {
+
+void
+callWithTimeout(std::chrono::steady_clock::duration timeout, std::function<void()> function)
+{
+    std::promise<void> promise;
+    auto future = promise.get_future();
+    std::thread t([&promise, &function] {
+        function();
+        promise.set_value();
+    });
+    if (future.wait_for(timeout) == std::future_status::timeout) {
+        FAIL() << "Timeout " << std::chrono::duration_cast<std::chrono::milliseconds>(timeout).count() << "ms exceeded";
+    }
+    t.join();
+}
+
+}  // namespace tests::common::util