qt: Implement Qt frontend to web browser

Using a custom reimplementation of QWebEngineView and an injector script.

src/yuzu/applets/web_browser.h

@@ -0,0 +1,45 @@
+// Copyright 2018 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+#include <QObject>
+#include <QWebEngineView>
+#include "core/frontend/applets/web_browser.h"
+
+class GMainWindow;
+
+QString GetNXShimInjectionScript();
+
+class NXInputWebEngineView : public QWebEngineView {
+public:
+    NXInputWebEngineView(QWidget* parent = nullptr);
+
+protected:
+    void keyPressEvent(QKeyEvent* event) override;
+    void keyReleaseEvent(QKeyEvent* event) override;
+};
+
+class QtWebBrowser final : public QObject, public Core::Frontend::WebBrowserApplet {
+    Q_OBJECT
+
+public:
+    explicit QtWebBrowser(GMainWindow& main_window);
+    ~QtWebBrowser() override;
+
+    void OpenPage(std::string_view url, std::function<void()> unpack_romfs_callback,
+                  std::function<void()> finished_callback) const override;
+
+signals:
+    void MainWindowOpenPage(std::string_view filename, std::string_view additional_args) const;
+
+public slots:
+    void MainWindowUnpackRomFS();
+    void MainWindowFinishedBrowsing();
+
+private:
+    mutable std::function<void()> unpack_romfs_callback;
+    mutable std::function<void()> finished_callback;
+};