NOISSUE FTB pack code implementation, cleaned up

api/logic/modplatform/ftb/FtbPrivatePackManager.h

@@ -0,0 +1,40 @@
+#pragma once
+
+#include <QSet>
+#include <QString>
+#include <QFile>
+#include "multimc_logic_export.h"
+
+class MULTIMC_LOGIC_EXPORT FtbPrivatePackManager
+{
+public:
+    ~FtbPrivatePackManager()
+    {
+        save();
+    }
+    void load();
+    void save() const;
+    bool empty() const
+    {
+        return currentPacks.empty();
+    }
+    const QSet<QString> &getCurrentPackCodes() const
+    {
+        return currentPacks;
+    }
+    void add(const QString &code)
+    {
+        currentPacks.insert(code);
+        dirty = true;
+    }
+    void remove(const QString &code)
+    {
+        currentPacks.remove(code);
+        dirty = true;
+    }
+
+private:
+    QSet<QString> currentPacks;
+    QString m_filename = "private_packs.txt";
+    mutable bool dirty = false;
+};