LibWeb: Add namespace qualifier to type names equal to a C++ namespace

For example, Document.getSelection returns Selection, which is in the
Selection namespace.

Namespaces.h has Linus' copyright since he changed the "is_one_of" list
to an Array.

Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/Namespaces.h

@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Array.h>
+#include <AK/StringView.h>
+
+namespace IDL {
+
+static constexpr Array libweb_interface_namespaces = {
+    "CSS"sv,
+    "Crypto"sv,
+    "DOM"sv,
+    "DOMParsing"sv,
+    "Encoding"sv,
+    "Fetch"sv,
+    "FileAPI"sv,
+    "Geometry"sv,
+    "HTML"sv,
+    "HighResolutionTime"sv,
+    "IntersectionObserver"sv,
+    "NavigationTiming"sv,
+    "RequestIdleCallback"sv,
+    "ResizeObserver"sv,
+    "SVG"sv,
+    "Selection"sv,
+    "UIEvents"sv,
+    "URL"sv,
+    "WebGL"sv,
+    "WebIDL"sv,
+    "WebSockets"sv,
+    "XHR"sv,
+};
+
+}