Structural cleanup

- Delete empty placeholder files: utils/dbHelpers.js, utils/logger.js, scripts/seedSets.js
- Merge newVersionController into importController (importFullDatabase belongs with import logic)
- Delete newVersionController.js
- Update importRoutes.js to import from importController

src/routes/importRoutes.js

@@ -1,7 +1,6 @@
 const express = require('express');
 const router = express.Router();
-const { importSets, importCards} = require('../controllers/importController');
-const { importFullDatabase } = require('../controllers/newVersionController');
+const { importSets, importCards, importFullDatabase } = require('../controllers/importController');
 
 router.post('/sets', importSets);
 router.post('/cards', importCards);