LibCore+RequestServer: Add support for SOCKS5 proxies

Userland/Libraries/LibCore/Proxy.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2022, Ali Mohammad Pur <mpfard@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Error.h>
+#include <AK/Types.h>
+#include <LibIPC/Forward.h>
+
+namespace Core {
+// FIXME: Username/password support.
+struct ProxyData {
+    enum Type {
+        Direct,
+        SOCKS5,
+    } type { Type::Direct };
+
+    u32 host_ipv4 { 0 };
+    int port { 0 };
+
+    bool operator==(ProxyData const& other) const = default;
+};
+}
+
+namespace IPC {
+bool encode(Encoder&, Core::ProxyData const&);
+ErrorOr<void> decode(Decoder&, Core::ProxyData&);
+}