feat: Add Fragment API for TON topups, Telegram Premium purchases, and Stars transactions

- Implemented Fragment API with methods for TON topups, Premium gifts, and Stars purchases.
- Created configuration management using environment variables.
- Added detailed README documentation for installation, configuration, and usage.
- Developed utility classes for API client, wallet linking, and transaction processing.
- Included example usage in main.py for easy demonstration of API functionalities.
- Updated requirements.txt with necessary dependencies.

.env.example

@@ -0,0 +1,11 @@
+# Fragment.com cookies - copy from browser after login (Header String format)
+# IMPORTANT: Use quotes to prevent semicolons from being treated as comments
+COOKIES = "your_fragment_cookies_here"
+
+HASH = 
+
+# TON wallet seed phrase - 12 or 24 words separated by spaces
+SEED = 
+
+# TON API key - get from https://tonconsole.com
+API_KEY =