[Feature Request] Implement async methods in Bunq C# SDK

[SvenLauterbach]

It seems that the Bunq C# SDK does not support async methods. In fact it uses .Result to make asynchronous network calls synchronous. Example in ApiClient.cs:

HttpResponseMessage result = this.client.SendAsync(requestMessage).Result;

It would be great if the Bunq SDK could switch to async method. This could improve performance/scalability for consuming applications. Also, the async/await programming model is now quite established in the .NET ecosystem.