Ladybird+LibWebView: Extract common JS console functionality to a helper

This creates WebView::ConsoleClient to handle functionality that will be
common to the JS consoles of all Ladybird chromes. This will let each
chrome focus on just the UI.

Note that this includes the `console.group` functionality that only the
Serenity chrome previously had. This was a FIXME in the Qt chrome, and
it is implemented such that all chromes will receive this functionality
for free.

Userland/Libraries/LibWebView/ConsoleClient.h

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2023, Tim Flynn <trflynn89@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/DeprecatedString.h>
+#include <AK/Function.h>
+#include <AK/Span.h>
+#include <AK/StringView.h>
+#include <AK/Vector.h>
+#include <LibWebView/Forward.h>
+
+namespace WebView {
+
+class ConsoleClient {
+public:
+    explicit ConsoleClient(ViewImplementation& content_web_view, ViewImplementation& console_web_view);
+    ~ConsoleClient();
+
+    void execute(StringView);
+
+    void clear();
+    void reset();
+
+private:
+    void handle_console_message(i32 message_index);
+    void handle_console_messages(i32 start_index, ReadonlySpan<DeprecatedString> message_types, ReadonlySpan<DeprecatedString> messages);
+
+    void print_source(StringView);
+    void print_html(StringView);
+
+    void request_console_messages();
+    void request_console_messages(i32 start_index);
+
+    void begin_group(StringView label, bool start_expanded);
+    void end_group();
+
+    ViewImplementation& m_content_web_view;
+    ViewImplementation& m_console_web_view;
+
+    i32 m_highest_notified_message_index { -1 };
+    i32 m_highest_received_message_index { -1 };
+    bool m_waiting_for_messages { false };
+
+    struct Group {
+        int id { 0 };
+        DeprecatedString label;
+    };
+    Vector<Group> m_group_stack;
+    int m_next_group_id { 1 };
+};
+
+}