feat(core,cli,mcp): Add MCP list_resources and read_resource core tools

[MrLesk]

Summary

This PR follows up on the base MCP Resources PR https://github.com/google-gemini/gemini-cli/pull/13178 and gives the model the possibility to automatically call MCP resources_list and resource_read whenever it's relevant for the conversation.

Features added:

• Add list_resources and read_resource core tools

Details

As agreed in https://github.com/google-gemini/gemini-cli/pull/13178, I am moving here the core tools implementation for MCP Resources. This will allow the model to automatically fetch the resources list and the detail when it considers relevant:

Related Issues

Related to #1459

How to Validate

I tested successfully with Backlog.md MCP Server resources and additionally with the @modelcontextprotocol/server-everything.

Pre-Merge Checklist

• [x] Updated relevant documentation and README (if needed)
• [x] Added/updated tests (if needed)
• [x] Noted breaking changes (if any)
• [ ] Validated on required platforms/methods:
  • [x] MacOS
    • [x] npm run
    • [ ] npx
    • [ ] Docker
    • [ ] Podman
    • [ ] Seatbelt
  • [ ] Windows
    • [ ] npm run
    • [ ] npx
    • [ ] Docker
  • [ ] Linux
    • [ ] npm run
    • [ ] npx
    • [ ] Docker