Class copy

launcher/FileSystem.h:105–157

* @brief Copies a directory and it's contents from src to dest */

 * @brief Copies a directory and it's contents from src to dest
 */
class copy : public QObject {
    Q_OBJECT
   public:
    copy(const QString& src, const QString& dst, QObject* parent = nullptr) : QObject(parent)
    {
        m_src.setPath(src);
        m_dst.setPath(dst);
    }
    copy& followSymlinks(const bool follow)
    {
        m_followSymlinks = follow;
        return *this;
    }
    copy& matcher(const IPathMatcher* filter)
    {
        m_matcher = filter;
        return *this;
    }
    copy& whitelist(bool whitelist)
    {
        m_whitelist = whitelist;
        return *this;
    }
    copy& overwrite(const bool overwrite)
    {
        m_overwrite = overwrite;
        return *this;
    }

    bool operator()(bool dryRun = false) { return operator()(QString(), dryRun); }

    qsizetype totalCopied() { return m_copied; }
    qsizetype totalFailed() { return m_failedPaths.length(); }
    QStringList failed() { return m_failedPaths; }

   signals:
    void fileCopied(const QString& relativeName);
    void copyFailed(const QString& relativeName);
    // TODO: maybe add a "shouldCopy" signal in the future?

   private:
    bool operator()(const QString& offset, bool dryRun = false);

   private:
    bool m_followSymlinks = true;
    const IPathMatcher* m_matcher = nullptr;
    bool m_whitelist = false;
    bool m_overwrite = false;
    QDir m_src;
    QDir m_dst;
    qsizetype m_copied;
    QStringList m_failedPaths;
};

struct LinkPair {
    QString src;