feat: Implement marketplace and purchases services

- Added MarketplaceService for searching usernames, numbers, and gifts.
- Introduced PurchasesService for purchasing stars and premium subscriptions.
- Created WalletService for wallet operations including balance checks and top-ups.
- Developed transaction handling for TON and USDT transfers.
- Added models for payments, marketplace results, and wallet information.
- Implemented error handling for various operations including wallet and transaction errors.
- Established domain structure for purchases, marketplace, and wallet functionalities.

pyfragment/models/wallet.py

@@ -0,0 +1,40 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+
+
+@dataclass
+class WalletInfo:
+    address: str
+    state: str
+    ton_balance: float
+    usdt_balance: float
+
+    def __repr__(self) -> str:
+        return (
+            f"WalletInfo(address='{self.address}', state='{self.state}', "
+            f"ton_balance={self.ton_balance} TON, usdt_balance={self.usdt_balance} USDT)"
+        )
+
+
+@dataclass
+class TonTransferResult:
+    transaction_id: str
+    destination: str
+    amount: int
+
+    def __repr__(self) -> str:
+        return f"TonTransferResult(destination='{self.destination}', amount={self.amount} TON, tx='{self.transaction_id}')"
+
+
+@dataclass
+class UsdtTransferResult:
+    transaction_id: str
+    destination: str
+    amount: int
+
+    def __repr__(self) -> str:
+        return f"UsdtTransferResult(destination='{self.destination}', amount={self.amount} USDT, tx='{self.transaction_id}')"
+
+
+__all__ = ["TonTransferResult", "UsdtTransferResult", "WalletInfo"]