MCP endpoints

**User story**

MCP (Model Context Protocol) is an open protocol that standardizes how applications provide context to LLMs. The LLMs connect to the MCP server to lookup and access agentic tools.

In a test scenario Citrus should be able to provide the MCP server as a simulated instance. The Citrus MCP server is able to verify incoming requests and provide a list of available tools. Further more the MCP server is able to simulate tool responses to an LLM.

**Additional context**

Evaluate client side MCP support in Citrus

The issue names no files, tests, or entry points. Start by evaluating client-side MCP support in Citrus, then determine how a simulated MCP server should verify requests, list tools, and provide tool responses. Done means the scope and expected behavior for MCP endpoint support are defined and testable.

Written by the indexing model from the issue text.