feat: add MCP search agent

[MuggleJinx]

Description

Close #2035. Implement the agent with ability to search for right MCP tools for the task, and execute it using Smithery registry. In the future, we can add more MCP registry.

Checklist

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• [x] I have read the CONTRIBUTION guide (required)
• [x] I have linked this PR to an issue using the Development section on the right sidebar or by adding Fixes #issue-number in the PR description (required)
• [x] I have checked if any dependencies need to be added or updated in pyproject.toml and uv lock
• [ ] I have updated the tests accordingly (required for a bug fix or a new feature)
• [x] I have updated the documentation if needed:
• [x] I have added examples if this is a new feature

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