Implement SEP-973: Icons and metadata support

[devcrocod]

Description

This issue tracks the implementation of modelcontextprotocol/modelcontextprotocol#955 which adds support for icons and additional metadata for Implementations, Resources, Tools, and Prompts.

Summary

SEP-973 introduces optional icon support and website URLs to help clients visually identify MCP servers and their capabilities. This includes:

• Icons for server implementations (multiple sizes supported)
• Icons for individual resources, tools, and prompts
• Website URLs for documentation linking

Implementation Requirements

• Add optional icons field to server metadata (supporting multiple MIME types and sizes)
• Add optional websiteUrl field for documentation links
• Update Resources, Tools, and Prompts to support icon metadata
• Ensure backward compatibility (all fields are optional)

Reference

• PR: SEP-973: Expose additional metadata for Implementations, Resources, Tools and Prompts modelcontextprotocol#955
• Specification changes will be merged soon