Libraries+Ladybird: Rename LibProtocol -> LibRequests

The identifier "Protocol" is claimed by Objective-C and Swift for use
by the language's built-in protocol conformance feature, which is
similar to Rust traits or Java interfaces.

Rename LibProtocol -> LibRequests, and its namespace from Protocol to
Requests to accomodate this.

Userland/Libraries/LibRequests/WebSocket.cpp

@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2021, Dex♪ <dexes.ttp@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibRequests/RequestClient.h>
+#include <LibRequests/WebSocket.h>
+
+namespace Requests {
+
+WebSocket::WebSocket(RequestClient& client, i32 connection_id)
+    : m_client(client)
+    , m_connection_id(connection_id)
+{
+}
+
+WebSocket::ReadyState WebSocket::ready_state()
+{
+    return static_cast<WebSocket::ReadyState>(m_client->websocket_ready_state(m_connection_id));
+}
+
+ByteString WebSocket::subprotocol_in_use()
+{
+    return m_client->websocket_subprotocol_in_use(m_connection_id);
+}
+
+void WebSocket::send(ByteBuffer binary_or_text_message, bool is_text)
+{
+    m_client->async_websocket_send(m_connection_id, is_text, move(binary_or_text_message));
+}
+
+void WebSocket::send(StringView text_message)
+{
+    send(ByteBuffer::copy(text_message.bytes()).release_value_but_fixme_should_propagate_errors(), true);
+}
+
+void WebSocket::close(u16 code, ByteString reason)
+{
+    m_client->async_websocket_close(m_connection_id, code, move(reason));
+}
+
+void WebSocket::did_open(Badge<RequestClient>)
+{
+    if (on_open)
+        on_open();
+}
+
+void WebSocket::did_receive(Badge<RequestClient>, ByteBuffer data, bool is_text)
+{
+    if (on_message)
+        on_message(WebSocket::Message { move(data), is_text });
+}
+
+void WebSocket::did_error(Badge<RequestClient>, i32 error_code)
+{
+    if (on_error)
+        on_error((WebSocket::Error)error_code);
+}
+
+void WebSocket::did_close(Badge<RequestClient>, u16 code, ByteString reason, bool was_clean)
+{
+    if (on_close)
+        on_close(code, move(reason), was_clean);
+}
+
+void WebSocket::did_request_certificates(Badge<RequestClient>)
+{
+    if (on_certificate_requested) {
+        auto result = on_certificate_requested();
+        if (!m_client->websocket_set_certificate(m_connection_id, result.certificate, result.key))
+            dbgln("WebSocket: set_certificate failed");
+    }
+}
+}