Add Azure Dall-E

[xbotter]

Motivation and Context

Implement Azure OpenAI Dall E

Description

There is no official SDK for Azure OpenAI Dall-E, nor are there any related documents. Therefore, I can only implement the API of Azure OpenAI Dall-E based on the examples provided by Azure OpenAI Studio, so that it can be used in SK.

Due to the differences between the API of Azure OpenAI Dall-E and OpenAI Dall-E, some modifications have been made to OpenAIClientBase under CustomClient to ensure compatibility.

Contribution Checklist

• [x] The code builds clean without any errors or warnings
• [x] The PR follows SK Contribution Guidelines (https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
• [x] The code follows the .NET coding conventions (https://learn.microsoft.com/dotnet/csharp/fundamentals/coding-style/coding-conventions) verified with dotnet format
• [x] All unit tests pass, and I have added new tests where possible
• [x] I didn't break anyone :smile: