Improve empty value handling in JSON, TSV and SQL readers

- Add emptyValue parameter to specify how to handle empty values (undefined, 0, null, NaN)
- Enhance null and empty value processing in all readers
- Add convertType function for automatic data type detection
- Add tests for empty value handling
- Add examples demonstrating readers with different parameters
- Align structure and logic of SQL, JSON and TSV readers with CSV and Excel readers

Author: a3ka

package.json

@@ -64,6 +64,8 @@
     "husky": "9.1.7",
     "lint-staged": "15.5.1",
     "prettier": "3.5.3",
+    "sqlite": "^5.1.1",
+    "sqlite3": "^5.1.7",
     "vitest": "^3.1.2",
     "xlsx": "^0.18.5"
   },