Ladybird: Rename classes ending with Ladybird

Now that all the classes for Ladybird are in the Ladybird namespace, we
don't need them named as Ladybird::FooBarLadybird. For the Qt-specific
classes, we can tack on a Qt at the end for clarity, but FontPlugin and
ImageCodecPlugin no longer have anything to do with Qt.

Ladybird/ImageCodecPlugin.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (c) 2022, Dex♪ <dexes.ttp@gmail.com>
+ * Copyright (c) 2022, Andreas Kling <kling@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/Platform/ImageCodecPlugin.h>
+
+namespace Ladybird {
+
+class ImageCodecPlugin final : public Web::Platform::ImageCodecPlugin {
+public:
+    ImageCodecPlugin() = default;
+    virtual ~ImageCodecPlugin() override;
+
+    virtual Optional<Web::Platform::DecodedImage> decode_image(ReadonlyBytes data) override;
+};
+
+}