add launcher folder and some checks to it

launcherbackend.h

@@ -90,7 +90,7 @@ private:
     {
         int id = 0;
         QString name, login, password;
-        QString authType = QStringLiteral("offline");   // offline | elyby
+        QString authType = QStringLiteral("offline"); // offline | elyby
         QString clientToken, accessToken, uuid, resolvedName, userType;
     };
     struct Version
@@ -101,11 +101,11 @@ private:
 
     void loadData();
     void loadSettings();
+    void ensureDataFiles();
     void saveProfiles();
     void saveVersions();
     void saveSettings();
 
-    QString defaultMinecraftDir() const;
     QString gameDir() const;
     QString versionIdOf(const Version &version) const;
 
@@ -117,7 +117,7 @@ private:
     QList<Profile> m_profiles;
     QList<Version> m_versions;
     QVariantMap m_settings;
-    QString m_dataDir;
+    QString m_storageError;
     int m_nextProfileId = 1;
     int m_nextVersionId = 1;