[Feature Request] Async support for REST API

Currently, the Binance Python SDK relies on the synchronous `requests` library for its REST API operations. This makes it challenging to integrate with asynchronous Python applications and frameworks.

- Please consider adding support for async REST API operations to the SDK, such as by providing an async client or refactoring key functionality to use an async HTTP library (e.g., `httpx`, which supports both sync and async).
- This enhancement would greatly benefit developers who need high concurrency with Binance services but cannot use WebSocket.
- Maintaining backwards compatibility with synchronous usage would be ideal.

Thank you for considering this feature!

Beginne mit der Überprüfung des synchronen REST-Clients des SDK und seiner Verwendung der requests-Bibliothek. Vergleiche anschließend Optionen für asynchrone HTTP-Bibliotheken wie httpx. Als abgeschlossen gilt, dass asynchrone REST-Operationen für Binance-Dienste verfügbar sind, während die bestehende synchrone Nutzung kompatibel bleibt.

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