LibWeb: Use rect value in CSS clip property

When a rect value is passed to the clip property via CSS, keep it in
ComputedValues so that at a later stage can make use of it.

Userland/Libraries/LibWeb/CSS/Clip.cpp

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2022, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "Clip.h"
+#include <LibWeb/CSS/StyleValue.h>
+
+namespace Web::CSS {
+
+Clip::Clip(Type type, EdgeRect edge_rect)
+    : m_type(type)
+    , m_edge_rect(edge_rect)
+{
+}
+
+Clip::Clip(EdgeRect edge_rect)
+    : m_type(Type::Rect)
+    , m_edge_rect(edge_rect)
+{
+}
+
+Clip Clip::make_auto()
+{
+    return Clip(Type::Auto, EdgeRect { Length::make_auto(), Length::make_auto(), Length::make_auto(), Length::make_auto() });
+}
+
+}