refactor/some core files to .ts + update some imports in commands

tsconfig.json

@@ -9,7 +9,12 @@
         "skipLibCheck": true,
         "resolveJsonModule": true,
         "forceConsistentCasingInFileNames": true,
-        "allowJs": true
+        "allowJs": true,
+        "baseUrl": "./src",
+        "paths": {
+            "@util/*": ["util/*"],
+            "@db/*": ["database/*"]
+        }
     },
     "include": ["src"],
     "exclude": ["node_modules"]