Refactor VNDB Telegram Bot

- Remove config.py and integrate environment variable handling directly in docker-compose.yml.
- Delete detailed_handlers.py and replace with simplified command handlers.
- Update requirements.txt to use aiogram and httpx instead of python-telegram-bot and requests.
- Remove test_bot.py and utils.py, consolidating functionality into new VNDBClient class.
- Implement VNDBClient for API interactions, simplifying query methods for visual novels, characters, and releases.
- Clean up docker-compose.yml for improved readability and maintainability.

requirements.txt

@@ -1,6 +1,2 @@
-python-telegram-bot==21.0
-python-dotenv==1.0.0
-aiohttp==3.9.1
-requests==2.31.0
-pytest==7.4.0
-pytest-asyncio==0.21.0
+aiogram==3.6.0
+httpx==0.27.0