feat: Add _meta field support to tool UI

[erichoracek]

Shows _meta fields if present when listing and calling tools

Motivation and Context

Allows MCP inspector users to view metadata returned when listing and calling tools.

How Has This Been Tested?

Tested with a server that populates these fields and noted that they were visible in the UI

Breaking Changes

N/A

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

Listing tools

Calling tools