chore: replace naive mangohud detection with vulkan layer detection

Signed-off-by: Jan200101 <sentrycraft123@gmail.com>

launcher/MangoHud.h

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-3.0-only
+/*
+ *  PrismLauncher - Minecraft Launcher
+ *  Copyright (C) 2022 Jan Drögehoff <sentrycraft123@gmail.com>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <QString>
+#include <QStringList>
+
+namespace MangoHud {
+
+QString getLibraryString();
+}