Ladybird: Make LocationEdit its own class

Also make return key behave more like other browsers when editing

Ladybird/LocationEdit.h

@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2023, Cameron Youell <cameronyouell@gmail.com>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#define AK_DONT_REPLACE_STD
+
+#include <QLineEdit>
+
+class Tab;
+
+class LocationEdit final : public QLineEdit {
+    Q_OBJECT
+public:
+    explicit LocationEdit(Tab*);
+};