Add tool result _meta in tool response and access in the ui

[zekebergida]

Include _meta in tool output and access it from the ui

Motivation and Context

While the docs specify that tooloutput _meta is forwarded to the ui and hidden from the model some providers including the basic host in this repo fail to make the _meta available to the ui. This PR will help demonstrate the functionality and can help others troubleshoot this.

How Has This Been Tested?

Claude.ai does forward tool output meta to the ui however chatgpt does not and there are ongoing discussions in developer communities for how to troubleshoot this

Breaking Changes

No

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context