MCP Server -> add prompts

[amri369]

Please read this first

• Have you read the docs?Agents SDK docs
• Have you searched for related issues? Others may have had similar requests

Describe the feature

The existing implementation of _MCPServerWithClientSession doesn't support prompts fetching from servers. This feature is needed to access to MCP Servers Prompts using Openai Agents SDK MCP Servers implementation.

[amri369]

#1013